METHODS, APPARATUS AND SYSTEMS FOR SUPPORTING MOBILE INITIATED CONNECTION ONLY (MICO) WIRELESS TRANSMIT/RECEIVE UNITS (WTRUs)

ABSTRACT

Methods, apparatus and systems for managing a connection state of a Wireless Transmit/Receive Unit (WTRU) that is in Mobile Initiated Communication Only (MICO) mode are disclosed. One representative method may include the WTRU obtaining information indicating that the WTRU is to initiate registration prior to sending a Service Request (SR). The representative method may further include the WTRU sending a registration request in accordance with the obtained information and sending a SR after registering with a Network Entity.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional PatentApplication No. 62/502,043 filed on May 5, 2017, the contents of whichare hereby incorporated herein by reference as if fully set forth.

FIELD

The disclosure relates to the field of wireless communications and, moreparticularly, to methods, apparatus and systems for supporting MICOWTRUs (e.g., in 5G).

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the Detailed Descriptionbelow, given by way of example in conjunction with drawings appendedhereto. Figures in such drawings, like the detailed description, areexamples. As such, the Figures and the detailed description are not tobe considered limiting, and other equally effective examples arepossible and likely. Furthermore, like reference numerals in the Figuresindicate like elements, and wherein:

FIG. 1A is a system diagram illustrating an example communicationssystem in which one or more disclosed embodiments may be implemented;

FIG. 1B is a system diagram illustrating an example wirelesstransmit/receive unit (WTRU) that may be used within the communicationssystem illustrated herein in FIG. 1A according to an embodiment;

FIG. 1C is a system diagram illustrating an example radio access network(RAN) and an example core network (CN) that may be used within thecommunications system illustrated in FIG. 1A according to an embodiment;

FIG. 1D is a system diagram illustrating a further example RAN and afurther example CN that may be used within the communications systemillustrated in FIG. 1A according to an embodiment;

FIG. 1E is a system diagram illustrating another example radio accessnetwork and another example CN that may be used within thecommunications system illustrated in FIG. 1A;

FIG. 1F is a system diagram illustrating still another example radioaccess network and still another example CN that may be used within thecommunications system illustrated in FIG. 1A;

FIG. 2 is a diagram illustrating a representative MICO WTRU moving to anew serving AMF;

FIG. 3 is a diagram illustrating representative states including arepresentative RRC_INACTIVE state in a 5G New Radio;

FIG. 4 is a diagram illustrating a representative registrationprocedure;

FIG. 5 is a diagram illustrating a representative determinationprocedure;

FIG. 6 is a diagram illustrating another representative determinationprocedure;

FIG. 7 is a diagram illustrating a representative Service Request (SR)triggered WTRU context retrieval procedure;

FIG. 8 is a diagram illustrating a Registration/SR procedure;

FIG. 9 is a diagram illustrating a representative MICO WTRU-initiatedConnection release procedure;

FIG. 10 is a diagram illustrating a representative procedure in which aRAN is made aware of a MICO mode of a WTRU;

FIG. 11 is a diagram illustrating a representative procedure for a MICOWTRU to accept or reject RAN signaling;

FIG. 12 is a flowchart illustrating a representative method offacilitating a SR;

FIG. 13 is a flowchart illustrating another representative method offacilitating a SR;

FIG. 14 is a flowchart illustrating a further representative method offacilitating a SR;

FIG. 15 is a flowchart illustrating an additional representative methodof facilitating a SR;

FIG. 16 is a flowchart illustrating yet another representative method offacilitating a SR;

FIG. 17 is a flowchart illustrating yet a further representative methodof facilitating a SR;

FIG. 18 is a flowchart illustrating yet an additional representativemethod of accepting or rejecting a connection release;

FIG. 19 is a flowchart illustrating a representative method tofacilitate a registration;

FIG. 20 is a flowchart illustrating a representative method implementedby a NW to facilitate a SR;

FIG. 21 is a flowchart illustrating another representative methodimplemented by a NW when a WTRU is in MICO mode;

FIG. 22 is a flowchart illustrating a further representative methodimplemented by a NW to facilitate a connection request;

FIG. 23 is a flowchart illustrating an additional representative methodimplemented by a NW to facilitate a SR;

FIG. 24 is a flowchart illustrating a representative method implementedby a NW to facilitate a registration; and

FIG. 25 is a flowchart illustrating a representative method implementedby a RAN entity to facilitate a SR.

DETAILED DESCRIPTION

A detailed description of illustrative embodiments may now be describedwith reference to the figures. However, while the present invention maybe described in connection with representative embodiments, it is notlimited thereto and it is to be understood that other embodiments may beused or modifications and additions may be made to the describedembodiments for performing the same function of the present inventionwithout deviating therefrom.

Although the representative embodiments are generally shown hereafterusing wireless network architectures, any number of different networkarchitectures may be used including networks with wired componentsand/or wireless components, for example.

FIG. 1A is a diagram illustrating an example communications system 100in which one or more disclosed embodiments may be implemented. Thecommunications system 100 may be a multiple access system that providescontent, such as voice, data, video, messaging, broadcast, etc., tomultiple wireless users. The communications system 100 may enablemultiple wireless users to access such content through the sharing ofsystem resources, including wireless bandwidth. For example, thecommunications systems 100 may employ one or more channel accessmethods, such as code division multiple access (CDMA), time divisionmultiple access (TDMA), frequency division multiple access (FDMA),orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tailunique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM(UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC)and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, 102 d, a radioaccess network (RAN) 103/104/105/113, a CN 106/107/109/115, a publicswitched telephone network (PSTN) 108, the Internet 110, and othernetworks 112, though it will be appreciated that the disclosedembodiments contemplate any number of WTRUs, base stations, networks,and/or network elements. Each of the WTRUs 102 a, 102 b, 102 c, 102 dmay be any type of device configured to operate and/or communicate in awireless environment. By way of example, the WTRUs 102 a, 102 b, 102 c,102 d, any of which may be referred to as a “station” and/or a “STA”,may be configured to transmit and/or receive wireless signals and mayinclude user equipment (UE), a mobile station, a fixed or mobilesubscriber unit, a subscription-based unit, a pager, a cellulartelephone, a personal digital assistant (PDA), a smartphone, a laptop, anetbook, a personal computer, a wireless sensor, a hotspot or Mi-Fidevice, an Internet of Things (IoT) device, a watch or other wearable, ahead-mounted display (HMD), a vehicle, a drone, a medical device andapplications (e.g., remote surgery), an industrial device andapplications (e.g., a robot and/or other wireless devices operating inan industrial and/or an automated processing chain contexts), a consumerelectronics device, a device operating on commercial and/or industrialwireless networks, and the like. Any of the WTRUs 102 a, 102 b, 102 cand 102 d may be interchangeably referred to as a UE.

The communications systems 100 may also include a base station 114 aand/or a base station 114 b. Each of the base stations 114 a, 114 b maybe any type of device configured to wirelessly interface with at leastone of the WTRUs 102 a, 102 b, 102 c, 102 d to facilitate access to oneor more communication networks, such as the CN 106/107/109/115, theInternet 110, and/or the other networks 112. By way of example, the basestations 114 a, 114 b may be a base transceiver station (BTS), a Node-B,an eNode-B, a 5G access point (e.g., a gNB), a Home Node B, a HomeeNode-B, a NR Node B, a site controller, an access point (AP), awireless router, and the like. While the base stations 114 a, 114 b areeach depicted as a single element, it will be appreciated that the basestations 114 a, 114 b may include any number of interconnected basestations and/or network elements.

The base station 114 a may be part of the RAN 103/104/105/113, which mayalso include other base stations and/or network elements (not shown),such as a base station controller (BSC), a radio network controller(RNC), relay nodes, etc. The base station 114 a and/or the base station114 b may be configured to transmit and/or receive wireless signals onone or more carrier frequencies, which may be referred to as a cell (notshown). The cell may further be divided into cell sectors. Thesefrequencies may be in licensed spectrum, unlicensed spectrum, or acombination of licensed and unlicensed spectrum. A cell may providecoverage for a wireless service to a specific geographical area that maybe relatively fixed or that may change over time. The cell may furtherbe divided into cell sectors. For example, the cell associated with thebase station 114 a may be divided into three sectors. Thus, in oneembodiment, the base station 114 a may include three transceivers, e.g.,one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and mayutilize multiple transceivers for each sector of the cell. For example,beamforming may be used to transmit and/or receive signals in desiredspatial directions.

The base stations 114 a, 114 b may communicate with one or more of theWTRUs 102 a, 102 b, 102 c, 102 d over an air interface 115/116/117/119,which may be any suitable wireless communication link (e.g., radiofrequency (RF), microwave, centimeter wave, micrometer wave, infrared(IR), ultraviolet (UV), visible light, etc.). The air interface115/116/117/119 may be established using any suitable radio accesstechnology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 103/104/105/113 and the WTRUs102 a, 102 b, 102 c may implement a radio technology such as UniversalMobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA),which may establish the air interface 115/116/117/119 using widebandCDMA (WCDMA). WCDMA may include communication protocols such asHigh-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA mayinclude High-Speed Downlink (DL) Packet Access (HSDPA) and/or High-SpeedUL Packet Access (HSUPA).

In another embodiment, the base station 114 a and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Evolved UMTSTerrestrial Radio Access (E-UTRA), which may establish the air interface115/116/117/119 using Long Term Evolution (LTE) and/or LTE-Advanced(LTE-A), LTE-Advanced Pro (LTE-A Pro) and/or 5G New Radio (NR).

In an embodiment, the base station 114 a and the WTRUs 102 a, 102 b, 102c may implement a radio technology such as NR Radio Access, which mayestablish the air interface 119 using NR.

In an embodiment, the base station 114 a and the WTRUs 102 a, 102 b, 102c may implement multiple radio access technologies. For example, thebase station 114 a and the WTRUs 102 a, 102 b, 102 c may implement LTEradio access and NR radio access together, for instance using dualconnectivity (DC) principles. Thus, the air interface utilized by WTRUs102 a, 102 b, 102 c may be characterized by multiple types of radioaccess technologies and/or transmissions sent to/from multiple types ofbase stations (e.g., an eNB and a gNB).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,102 c may implement radio technologies such as IEEE 802.11 (i.e.,Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperabilityfor Microwave Access (WiMAX)), CDMA2000, CDMA2000 1×, CDMA2000 EV-DO,Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), InterimStandard 856 (IS-856), Global System for Mobile communications (GSM),Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and thelike.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode-B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, an industrialfacility, an air corridor (e.g., for use by drones), a roadway, and thelike. In one embodiment, the base station 114 b and the WTRUs 102 c, 102d may implement a radio technology such as IEEE 802.11 to establish awireless local area network (WLAN). In another embodiment, the basestation 114 b and the WTRUs 102 c, 102 d may implement a radiotechnology such as IEEE 802.15 to establish a wireless personal areanetwork (WPAN). In yet another embodiment, the base station 114 b andthe WTRUs 102 c, 102 d may utilize a cellular-based RAT (e.g., WCDMA,CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR etc.) to establish a picocellor femtocell. As shown in FIG. 1A, the base station 114 b may have adirect connection to the Internet 110. Thus, the base station 114 b maynot be required to access the Internet 110 via the CN 106/107/109/115.

The RAN 103/104/105/113 may be in communication with the CN106/107/109/115, which may be any type of network configured to providevoice, data, applications, and/or voice over internet protocol (VoIP)services to one or more of the WTRUs 102 a, 102 b, 102 c, 102 d. Thedata may have varying quality of service (QoS) requirements, such asdiffering throughput requirements, latency requirements, error tolerancerequirements, reliability requirements, data throughput requirements,mobility requirements, and the like. For example, the CN 106/107/109/115may provide call control, billing services, mobile location-basedservices, pre-paid calling, Internet connectivity, video distribution,etc., and/or perform high-level security functions, such as userauthentication. Although not shown in FIG. 1A, it will be appreciatedthat the RAN 103/104/105/113 and/or the CN 106/107/109/115 may be indirect or indirect communication with other RANs that employ the sameRAT as the RAN 103/104/105/113 or a different RAT. For example, inaddition to being connected to the RAN 103/104/105/113, which may beutilizing an NR or E-UTRA radio technology, the CN 106/107/109/115 mayalso be in communication with another RAN (not shown) employing a GSM,UMTS, CDMA 2000, WiMAX, or WiFi radio technology.

The CN 106/107/109/115 may also serve as a gateway for the WTRUs 102 a,102 b, 102 c, 102 d to access the PSTN 108, the Internet 110, and/or theother networks 112. The PSTN 108 may include circuit-switched telephonenetworks that provide plain old telephone service (POTS). The Internet110 may include a global system of interconnected computer networks anddevices that use common communication protocols, such as thetransmission control protocol (TCP), user datagram protocol (UDP) and/orthe internet protocol (IP) in the TCP/IP internet protocol suite. Thenetworks 112 may include wired and/or wireless communications networksowned and/or operated by other service providers. For example, thenetworks 112 may include another CN connected to one or more RANs, whichmay employ the same RAT as the RAN 103/104/105/113 or a different RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities (e.g., theWTRUs 102 a, 102 b, 102 c, 102 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks). For example, the WTRU 102 c shown in FIG. 1A may be configuredto communicate with the base station 114 a, which may employ acellular-based radio technology, and with the base station 114 b, whichmay employ an IEEE 802 radio technology. Some or all of the WTRUs 102 a,102 b, 102 c, 102 d in the communication system 100 may communicate withother devices using, for example Bluetooth technology.

FIG. 1B is a system diagram illustrating an example WTRU 102. As shownin FIG. 1B, the WTRU 102 may include a processor 118, a transceiver 120,a transmit/receive element 122, a speaker/microphone 124, a keypad 126,a display/touchpad 128, non-removable memory 130, removable memory 132,a power source 134, a global positioning system (GPS) chipset 136, aninterference management unit 139 and/or other peripherals 138, amongothers. It will be appreciated that the WTRU 102 may include anysub-combination of the foregoing elements while remaining consistentwith an embodiment.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto and/or receive signals from, a base station (e.g., the base station114 a) over the air interface 115/116/117/119. For example, in oneembodiment, the transmit/receive element 122 may be an antennaconfigured to transmit and/or receive RF signals. In another embodiment,the transmit/receive element 122 may be an emitter/detector configuredto transmit and/or receive IR, UV, or visible light signals, forexample. In yet another embodiment, the transmit/receive element 122 maybe configured to transmit and/or receive both RF and light signals. Itwill be appreciated that the transmit/receive element 122 may beconfigured to transmit and/or receive any combination of wirelesssignals.

Although the transmit/receive element 122 is depicted in FIG. 1B as asingle element, the WTRU 102 may include any number of transmit/receiveelements 122. More specifically, the WTRU 102 may employ MIMOtechnology. Thus, in one embodiment, the WTRU 102 may include two ormore transmit/receive elements 122 (e.g., multiple antennas) fortransmitting and/or receiving wireless signals over the air interface115/116/117/119.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and/or todemodulate the signals that are received by the transmit/receive element122. As noted above, the WTRU 102 may have multi-mode capabilities.Thus, the transceiver 120 may include multiple transceivers for enablingthe WTRU 102 to communicate via multiple RATs, such as NR, UTRA and/orIEEE 802.11, for example.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and/or store data in, any type of suitablememory, such as the non-removable memory 130 and/or the removable memory132. The non-removable memory 130 may include random-access memory(RAM), read-only memory (ROM), a hard disk, or any other type of memorystorage device. The removable memory 132 may include a subscriberidentity module (SIM) card, a memory stick, a secure digital (SD) memorycard, and the like. In other embodiments, the processor 118 may accessinformation from, and/or store data in, memory that is not physicallylocated on the WTRU 102, such as on a server or a home computer (notshown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may be coupled to the GPS chipset 136, which may beconfigured to provide location information (e.g., longitude and/orlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface115/116/117/119 from a base station (e.g., base stations 114 a, 114 b)and/or may determine its location based on the timing of the signalsbeing received from two or more nearby base stations. It will beappreciated that the WTRU 102 may acquire location information by way ofany suitable location-determination method while remaining consistentwith an embodiment.

The processor 118 may be coupled to other peripherals 138, which mayinclude one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs and/or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, a Virtual Reality and/or Augmented Reality (VR/AR) device, anactivity tracker, and the like. The peripherals 138 may include one ormore sensors, the sensors may be one or more of a gyroscope, anaccelerometer, a hall effect sensor, a magnetometer, an orientationsensor, a proximity sensor, a temperature sensor, a time sensor; ageolocation sensor; an altimeter, a light sensor, a touch sensor, amagnetometer, a barometer, a gesture sensor, a biometric sensor, and/ora humidity sensor and the like.

The processor 118 of the WTRU 102 may operatively communicate withvarious peripherals 138 including, for example, any of: the one or moreaccelerometers, the one or more gyroscopes, the USB port, othercommunication interfaces/ports, the display and/or other visual/audioindicators to implement representative embodiments disclosed herein.

The WTRU 102 may include a full duplex radio for which transmission andreception of some or all of the signals (e.g., associated withparticular subframes for both the UL (e.g., for transmission) anddownlink (e.g. for reception) may be, for example partially or fully,concurrent and/or simultaneous. The full duplex radio may include aninterference management unit 139 to reduce and/or substantiallyeliminate self-interference via either hardware (e.g., a choke) orsignal processing via a processor (e.g., a separate processor (notshown) or via processor 118). In an embodiment, the WTRU 102 may includea half-duplex radio for transmission and reception of some or all of thesignals (e.g., associated with particular subframes for either the UL(e.g., for transmission) or the downlink (e.g., for reception)).

FIG. 1C is a system diagram illustrating the RAN 103 and the CN 106according to another embodiment. As noted above, the RAN 103 may employa UTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102c over the air interface 115. The RAN 103 may also be in communicationwith the CN 106. As shown in FIG. 1C, the RAN 103 may include Node-Bs140 a, 140 b, 140 c, which may each include one or more transceivers forcommunicating with the WTRUs 102 a, 102 b, 102 c over the air interface115. The Node-Bs 140 a, 140 b, 140 c may each be associated with aparticular cell (not shown) within the RAN 103. The RAN 103 may alsoinclude RNCs 142 a, 142 b. It will be appreciated that the RAN 103 mayinclude any number of Node-Bs and RNCs while remaining consistent withan embodiment.

As shown in FIG. 1C, the Node-Bs 140 a, 140 b may be in communicationwith the RNC 142 a. Additionally, the Node-B 140 c may be incommunication with the RNC 142 b. The Node-Bs 140 a, 140 b, 140 c maycommunicate with the respective RNCs 142 a, 142 b via an Iub interface.The RNCs 142 a, 142 b may be in communication with one another via anIur interface. Each of the RNCs 142 a, 142 b may be configured tocontrol the respective Node-Bs 140 a, 140 b, 140 c to which it isconnected. In addition, each of the RNCs 142 a, 142 b may be configuredto carry out or support other functionality, such as outer loop powercontrol, load control, admission control, packet scheduling, handovercontrol, macrodiversity, security functions, data encryption, and thelike.

The CN 106 shown in FIG. 1C may include a media gateway (MGW) 144, amobile switching center (MSC) 146, a serving GPRS support node (SGSN)148, and/or a gateway GPRS support node (GGSN) 150. While each of theforegoing elements are depicted as part of the CN 106, it will beappreciated that any one of these elements may be owned and/or operatedby an entity other than the CN operator.

The RNC 142 a in the RAN 103 may be connected to the MSC 146 in the CN106 via an IuCS interface. The MSC 146 may be connected to the MGW 144.The MSC 146 and the MGW 144 may provide the WTRUs 102 a, 102 b, 102 cwith access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices.

The RNC 142 a in the RAN 103 may also be connected to the SGSN 148 inthe CN 106 via an IuPS interface. The SGSN 148 may be connected to theGGSN 150. The SGSN 148 and the GGSN 150 may provide the WTRUs 102 a, 102b, 102 c with access to packet-switched networks, such as the Internet110, to facilitate communications between and the WTRUs 102 a, 102 b,102 c and IP-enabled devices.

As noted above, the CN 106 may also be connected to the other networks112, which may include other wired and/or wireless networks that areowned and/or operated by other service providers.

FIG. 1D is a system diagram illustrating the RAN 104 and the CN 107according to an embodiment. As noted above, the RAN 104 may employ anE-UTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102c over the air interface 116. The RAN 104 may also be in communicationwith the CN 107.

The RAN 104 may include eNode-Bs 160 a, 160 b, 160 c, though it will beappreciated that the RAN 104 may include any number of eNode-Bs whileremaining consistent with an embodiment. The eNode-Bs 160 a, 160 b, 160c may each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the eNode-Bs 160 a, 160 b, 160 c may implement MIMO technology. Thus,the eNode-B 160 a, for example, may use multiple antennas to transmitwireless signals to, and/or receive wireless signals from, the WTRU 102a.

Each of the eNode-Bs 160 a, 160 b, 160 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the UL and/or DL, and the like. As shown in FIG. 1D, the eNode-Bs 160a, 160 b, 160 c may communicate with one another over an X2 interface.The eNode-B may include a full duplex radio similar to that of the WTRU102 (e.g., with an interference management unit). The CN 107 shown inFIG. 1D may include a mobility management entity (MME) 162, a servinggateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166.While each of the foregoing elements are depicted as part of the CN 107,it will be appreciated that any of these elements may be owned and/oroperated by an entity other than the CN operator.

The MME 162 may be connected to each of the eNode-Bs 160 a, 160 b, 160 cin the RAN 104 via an S1 interface and may serve as a control node. Forexample, the MME 162 may be responsible for authenticating users of theWTRUs 102 a, 102 b, 102 c, bearer activation/deactivation, selecting aparticular serving gateway during an initial attach of the WTRUs 102 a,102 b, 102 c, and the like. The MME 162 may provide a control planefunction for switching between the RAN 104 and other RANs (not shown)that employ other radio technologies, such as GSM and/or WCDMA.

The serving gateway 164 may be connected to each of the eNode-Bs 160 a,160 b, 160 c in the RAN 104 via the S1 interface. The serving gateway164 may generally route and forward user data packets to/from the WTRUs102 a, 102 b, 102 c. The serving gateway 164 may perform otherfunctions, such as anchoring user planes during inter-eNode-B handovers,triggering paging when DL data is available for the WTRUs 102 a, 102 b,102 c, managing and storing contexts of the WTRUs 102 a, 102 b, 102 c,and the like.

The serving gateway 164 may be connected to the PDN gateway 166, whichmay provide the WTRUs 102 a, 102 b, 102 c with access to packet-switchednetworks, such as the Internet 110, to facilitate communications betweenthe WTRUs 102 a, 102 b, 102 c and IP-enabled devices.

The CN 107 may facilitate communications with other networks. Forexample, the CN 107 may provide the WTRUs 102 a, 102 b, 102 c withaccess to circuit-switched networks, such as the PSTN 108, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and traditionalland-line communications devices. For example, the CN 107 may include,or may communicate with, an IP gateway (e.g., an IP multimedia subsystem(IMS) server) that serves as an interface between the CN 107 and thePSTN 108. In addition, the CN 107 may provide the WTRUs 102 a, 102 b,102 c with access to the other networks 112, which may include otherwired and/or wireless networks that are owned and/or operated by otherservice providers.

FIG. 1E is a system diagram illustrating the RAN 105 and the CN 109according to an embodiment. The RAN 105 may be an access service network(ASN) that employs IEEE 802.16 radio technology to communicate with theWTRUs 102 a, 102 b, 102 c over the air interface 117. As will be furtherdiscussed below, the communication links between the differentfunctional entities of the WTRUs 102 a, 102 b, 102 c, the RAN 105, andthe CN 109 may be defined as reference points.

As shown in FIG. 1E, the RAN 105 may include base stations 170 a, 170 b,170 c, and an ASN gateway 182, though it will be appreciated that theRAN 105 may include any number of base stations and ASN gateways whileremaining consistent with an embodiment. The base stations 170 a, 170 b,170 c may each be associated with a particular cell (not shown) in theRAN 105 and may each include one or more transceivers for communicatingwith the WTRUs 102 a, 102 b, 102 c over the air interface 117. In oneembodiment, the base stations 170 a, 170 b, 170 c may implement MIMOtechnology. The base station 170 a, for example, may use multipleantennas to transmit wireless signals to, and/or receive wirelesssignals from, the WTRU 102 a. The base stations 170 a, 170 b, 170 c mayalso provide mobility management functions, such as handoff triggering,tunnel establishment, radio resource management, traffic classification,quality of service (QoS) policy enforcement, and the like. The ASNgateway 182 may serve as a traffic aggregation point and may beresponsible for paging, caching of subscriber profiles, routing to theCN 109, and the like.

The air interface 117 between the WTRUs 102 a, 102 b, 102 c and the RAN105 may be defined as an R1 reference point that implements the IEEE802.16 specification. In addition, each of the WTRUs 102 a, 102 b, 102 cmay establish a logical interface (not shown) with the CN 109. Thelogical interface between the WTRUs 102 a, 102 b, 102 c and the CN 109may be defined as an R2 reference point, which may be used forauthentication, authorization, IP host configuration management, and/ormobility management.

The communication link between each of the base stations 170 a, 170 b,170 c may be defined as an R8 reference point that includes protocolsfor facilitating WTRU handovers and the transfer of data between basestations. The communication link between the base stations 170 a, 170 b,170 c and the ASN gateway 182 may be defined as an R6 reference point.The R6 reference point may include protocols for facilitating mobilitymanagement based on mobility events associated with each of the WTRUs102 a, 102 b, 102 c.

As shown in FIG. 1E, the RAN 105 may be connected to the CN 109. Thecommunication link between the RAN 105 and the CN 109 may be defined asan R3 reference point that includes protocols for facilitating datatransfer and mobility management capabilities, for example. The CN 109may include a mobile IP home agent (MIP-HA) 184, an authentication,authorization, accounting (AAA) server 186, and a gateway 188. Whileeach of the foregoing elements are depicted as part of the CN 109, itwill be appreciated that any of these elements may be owned and/oroperated by an entity other than the CN operator.

The MIP-HA 184 may be responsible for IP address management, and mayenable the WTRUs 102 a, 102 b, 102 c to roam between different ASNsand/or different CNs. The MIP-HA 184 may provide the WTRUs 102 a, 102 b,102 c with access to packet-switched networks, such as the Internet 110,to facilitate communications between the WTRUs 102 a, 102 b, 102 c andIP-enabled devices. The AAA server 186 may be responsible for userauthentication and for supporting user services. The gateway 188 mayfacilitate interworking with other networks. For example, the gateway188 may provide the WTRUs 102 a, 102 b, 102 c with access tocircuit-switched networks, such as the PSTN 108, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and traditionalland-line communications devices. The gateway 188 may provide the WTRUs102 a, 102 b, 102 c with access to the other networks 112, which mayinclude other wired and/or wireless networks that are owned and/oroperated by other service providers.

Although not shown in FIG. 1E, it will be appreciated that the RAN 105may be connected to other ASNs, other RANs (e.g., RANs 103 and/or 104)and/or the CN 109 may be connected to other CNs (e.g., CN 106 and/or107). The communication link between the RAN 105 and the other ASNs maybe defined as an R4 reference point, which may include protocols forcoordinating the mobility of the WTRUs 102 a, 102 b, 102 c between theRAN 105 and the other ASNs. The communication link between the CN 109and the other CNs may be defined as an R5 reference, which may includeprotocols for facilitating interworking between home CNs and visitedCNs.

In representative embodiments, the other network 112 may be a WLAN.

A WLAN in Infrastructure Basic Service Set (BSS) mode may have an AccessPoint (AP) for the BSS and one or more stations (STAs) associated withthe AP. The AP may have an access or an interface to a DistributionSystem (DS) or another type of wired/wireless network that carriestraffic in to and/or out of the BSS. Traffic to STAs that originatesfrom outside the BSS may arrive through the AP and may be delivered tothe STAs. Traffic originating from STAs to destinations outside the BSSmay be sent to the AP to be delivered to respective destinations.Traffic between STAs within the BSS may be sent through the AP, forexample, where the source STA may send traffic to the AP and the AP maydeliver the traffic to the destination STA. The traffic between STAswithin a BSS may be considered and/or referred to as peer-to-peertraffic. The peer-to-peer traffic may be sent between (e.g., directlybetween) the source and destination STAs with a direct link setup (DLS).In certain representative embodiments, the DLS may use an 802.11e DLS oran 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS)mode may not have an AP, and the STAs (e.g., all of the STAs) within orusing the IBSS may communicate directly with each other. The IBSS modeof communication may sometimes be referred to herein as an “ad-hoc” modeof communication.

When using the 802.11ac infrastructure mode of operation or a similarmode of operations, the AP may transmit a beacon on a fixed channel,such as a primary channel. The primary channel may be a fixed width(e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling.The primary channel may be the operating channel of the BSS and may beused by the STAs to establish a connection with the AP. In certainrepresentative embodiments, Carrier Sense Multiple Access with CollisionAvoidance (CSMA/CA) may be implemented, for example in in 802.11systems. For CSMA/CA, the STAs (e.g., every STA), including the AP, maysense the primary channel. If the primary channel is sensed/detectedand/or determined to be busy by a particular STA, the particular STA mayback off. One STA (e.g., only one station) may transmit at any giventime in a given BSS.

High Throughput (HT) STAs may use a 40 MHz wide channel forcommunication, for example, via a combination of the primary 20 MHzchannel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHzwide channel.

Very High Throughput (VHT) STAs may support 20 MHz, 40 MHz, 80 MHz,and/or 160 MHz wide channels. The 40 MHz, and/or 80 MHz, channels may beformed by combining contiguous 20 MHz channels. A 160 MHz channel may beformed by combining 8 contiguous 20 MHz channels, or by combining twonon-contiguous 80 MHz channels, which may be referred to as an 80+80configuration. For the 80+80 configuration, the data, after channelencoding, may be passed through a segment parser that may divide thedata into two streams. Inverse Fast Fourier Transform (IFFT) processing,and time domain processing, may be done on each stream separately. Thestreams may be mapped on to the two 80 MHz channels, and the data may betransmitted by a transmitting STA. At the receiver of the receiving STA,the above described operation for the 80+80 configuration may bereversed, and the combined data may be sent to the Medium Access Control(MAC).

Sub 1 GHz modes of operation are supported by 802.11af and 802.11ah. Thechannel operating bandwidths, and carriers, are reduced in 802.11af and802.11ah relative to those used in 802.11n, and 802.11ac. 802.11afsupports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space(TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and16 MHz bandwidths using non-TVWS spectrum. According to a representativeembodiment, 802.11ah may support Meter Type Control/Machine-TypeCommunications, such as MTC devices in a macro coverage area. MTCdevices may have certain capabilities, for example, limited capabilitiesincluding support for (e.g., only support for) certain and/or limitedbandwidths. The MTC devices may include a battery with a battery lifeabove a threshold (e.g., to maintain a very long battery life).

WLAN systems, which may support multiple channels, and channelbandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include achannel which may be designated as the primary channel. The primarychannel may have a bandwidth equal to the largest common operatingbandwidth supported by all STAs in the BSS. The bandwidth of the primarychannel may be set and/or limited by a STA, from among all STAs inoperating in a BSS, which supports the smallest bandwidth operatingmode. In the example of 802.11ah, the primary channel may be 1 MHz widefor STAs (e.g., MTC type devices) that support (e.g., only support) a 1MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4MHz, 8 MHz, 16 MHz, and/or other channel bandwidth operating modes.Carrier sensing and/or Network Allocation Vector (NAV) settings maydepend on the status of the primary channel. If the primary channel isbusy, for example, due to a STA (which supports only a 1 MHz operatingmode), transmitting to the AP, the entire available frequency bands maybe considered busy even though a majority of the frequency bands remainsidle and may be available.

In the United States, the available frequency bands, which may be usedby 802.11ah, are from 902 MHz to 928 MHz. In Korea, the availablefrequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the availablefrequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidthavailable for 802.11ah is 6 MHz to 26 MHz depending on the country code.

FIG. 1F is a system diagram illustrating the RAN 113 and the CN 115according to an embodiment. As noted above, the RAN 113 may employ an NRradio technology to communicate with the WTRUs 102 a, 102 b, 102 c overthe air interface 119. The RAN 113 may also be in communication with theCN 115.

The RAN 113 may include gNBs 180 a, 180 b, 180 c, though it will beappreciated that the RAN 113 may include any number of gNBs whileremaining consistent with an embodiment. The gNBs 180 a, 180 b, 180 cmay each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 119. In one embodiment,the gNBs 180 a, 180 b, 180 c may implement MIMO technology. For example,gNBs 180 a, 108 b may utilize beamforming to transmit signals to and/orreceive signals from the gNBs 180 a, 180 b, 180 c. Thus, the gNB 180 a,for example, may use multiple antennas to transmit wireless signals to,and/or receive wireless signals from, the WTRU 102 a. In an embodiment,the gNBs 180 a, 180 b, 180 c may implement carrier aggregationtechnology. For example, the gNB 180 a may transmit multiple componentcarriers to the WTRU 102 a (not shown). A subset of these componentcarriers may be on unlicensed spectrum while the remaining componentcarriers may be on licensed spectrum. In an embodiment, the gNBs 180 a,180 b, 180 c may implement Coordinated Multi-Point (CoMP) technology.For example, WTRU 102 a may receive coordinated transmissions from gNB180 a and gNB 180 b (and/or gNB 180 c).

The WTRUs 102 a, 102 b, 102 c may communicate with gNBs 180 a, 180 b,180 c using transmissions associated with a scalable numerology. Forexample, the OFDM symbol spacing and/or OFDM subcarrier spacing may varyfor different transmissions, different cells, and/or different portionsof the wireless transmission spectrum. The WTRUs 102 a, 102 b, 102 c maycommunicate with gNBs 180 a, 180 b, 180 c using subframe or transmissiontime intervals (TTIs) of various or scalable lengths (e.g., containingvarying number of OFDM symbols and/or lasting varying lengths ofabsolute time).

The gNBs 180 a, 180 b, 180 c may be configured to communicate with theWTRUs 102 a, 102 b, 102 c in a standalone configuration and/or anon-standalone configuration. In the standalone configuration, WTRUs 102a, 102 b, 102 c may communicate with gNBs 180 a, 180 b, 180 c withoutalso accessing other RANs (e.g., such as eNode-Bs 160 a, 160 b, 160 c).In the standalone configuration, WTRUs 102 a, 102 b, 102 c may utilizeone or more of gNBs 180 a, 180 b, 180 c as a mobility anchor point. Inthe standalone configuration, WTRUs 102 a, 102 b, 102 c may communicatewith gNBs 180 a, 180 b, 180 c using signals in an unlicensed band. In anon-standalone configuration WTRUs 102 a, 102 b, 102 c may communicatewith/connect to gNBs 180 a, 180 b, 180 c while also communicatingwith/connecting to another RAN such as eNode-Bs 160 a, 160 b, 160 c. Forexample, WTRUs 102 a, 102 b, 102 c may implement DC principles tocommunicate with one or more gNBs 180 a, 180 b, 180 c and one or moreeNode-Bs 160 a, 160 b, 160 c substantially simultaneously. In thenon-standalone configuration, eNode-Bs 160 a, 160 b, 160 c may serve asa mobility anchor for WTRUs 102 a, 102 b, 102 c and gNBs 180 a, 180 b,180 c may provide additional coverage and/or throughput for servicingWTRUs 102 a, 102 b, 102 c.

Each of the gNBs 180 a, 180 b, 180 c may be associated with a particularcell (not shown) and may be configured to handle radio resourcemanagement decisions, handover decisions, scheduling of users in the ULand/or DL, support of network slicing, dual connectivity, interworkingbetween NR and E-UTRA, routing of user plane data towards User PlaneFunction (UPF) 184 a, 184 b, routing of control plane informationtowards Access and Mobility Management Function (AMF) 182 a, 182 b andthe like. As shown in FIG. 1F, the gNBs 180 a, 180 b, 180 c maycommunicate with one another over an Xn interface.

The CN 115 shown in FIG. 1F may include at least one AMF 182 a, 182 b,at least one UPF 184 a,184 b, at least one Session Management Function(SMF) 183 a, 183 b, and possibly a Data Network (DN) 185 a, 185 b. Whileeach of the foregoing elements are depicted as part of the CN 115, itwill be appreciated that any of these elements may be owned and/oroperated by an entity other than the CN operator.

The AMF 182 a, 182 b may be connected to one or more of the gNBs 180 a,180 b, 180 c in the RAN 113 via an N2 interface and may serve as acontrol node. For example, the AMF 182 a, 182 b may be responsible forauthenticating users of the WTRUs 102 a, 102 b, 102 c, support fornetwork slicing (e.g., handling of different PDU sessions with differentrequirements), selecting a particular SMF 183 a, 183 b, management ofthe registration area, termination of NAS signaling, mobilitymanagement, and the like. Network slicing may be used by the AMF 182 a,182 b in order to customize CN support for WTRUs 102 a, 102 b, 102 cbased on the types of services being utilized WTRUs 102 a, 102 b, 102 c.For example, different network slices may be established for differentuse cases such as services relying on ultra-reliable low latency (URLLC)access, services relying on enhanced massive mobile broadband (eMBB)access, services for machine type communication (MTC) access, and/or thelike. The AMF 182 may provide a control plane function for switchingbetween the RAN 113 and other RANs (not shown) that employ other radiotechnologies, such as LTE, LTE-A, LTE-A Pro, and/or non-3GPP accesstechnologies such as WiFi.

The SMF 183 a, 183 b may be connected to an AMF 182 a, 182 b in the CN115 via an N11 interface. The SMF 183 a, 183 b may also be connected toa UPF 184 a, 184 b in the CN 115 via an N4 interface. The SMF 183 a, 183b may select and control the UPF 184 a, 184 b and configure the routingof traffic through the UPF 184 a, 184 b. The SMF 183 a, 183 b mayperform other functions, such as managing and allocating WTRU IPaddress, managing PDU sessions, controlling policy enforcement and QoS,providing downlink data notifications, and the like. A PDU session typemay be IP-based, non-IP based, Ethernet-based, and the like.

The UPF 184 a, 184 b may be connected to one or more of the gNBs 180 a,180 b, 180 c in the RAN 113 via an N3 interface, which may provide theWTRUs 102 a, 102 b, 102 c with access to packet-switched networks, suchas the Internet 110, to facilitate communications between the WTRUs 102a, 102 b, 102 c and IP-enabled devices. The UPF 184, 184 b may performother functions, such as routing and forwarding packets, enforcing userplane policies, supporting multi-homed PDU sessions, handling user planeQoS, buffering downlink packets, providing mobility anchoring, and thelike.

The CN 115 may facilitate communications with other networks. Forexample, the CN 115 may include, or may communicate with, an IP gateway(e.g., an IP multimedia subsystem (IMS) server) that serves as aninterface between the CN 115 and the PSTN 108. In addition, the CN 115may provide the WTRUs 102 a, 102 b, 102 c with access to the othernetworks 112, which may include other wired and/or wireless networksthat are owned and/or operated by other service providers. In oneembodiment, the WTRUs 102 a, 102 b, 102 c may be connected to a localData Network (DN) 185 a, 185 b through the UPF 184 a, 184 b via the N3interface to the UPF 184 a, 184 b and an N6 interface between the UPF184 a, 184 b and the DN 185 a, 185 b.

Although the RAN 113 is disclosed herein as providing certainoperations, it is contemplated that the gNBs 180 a, 180 b and 180 cwhich are included in the RAN 113 may enable such operations.

Although the CN 115 is disclosed as providing certain operations, it iscontemplated that the AMFs 182 a, 182 b, the SMFs 183 a, 183 b and/orthe UPFs 184 a, 184 b which are included in the CN 115 may enable suchoperations.

In view of FIGS. 1A-1D, and the corresponding description of FIGS.1A-1D, one or more, or all, of the functions described herein withregard to one or more of: WTRU 102 a-d, Base Station 114 a-b, eNode-B160 a-c, MME 162, SGW 164, PGW 166, gNB 180 a-c, AMF 182 a-b, UPF 184a-b, SMF 183 a-b, DN 185 a-b, and/or any other device(s) describedherein, may be performed by one or more emulation devices (not shown).The emulation devices may be one or more devices configured to emulateone or more, or all, of the functions described herein. For example, theemulation devices may be used to test other devices and/or to simulatenetwork and/or WTRU functions.

The emulation devices may be designed to implement one or more tests ofother devices in a lab environment and/or in an operator networkenvironment. For example, the one or more emulation devices may performthe one or more, or all, functions while being fully or partiallyimplemented and/or deployed as part of a wired and/or wirelesscommunication network in order to test other devices within thecommunication network. The one or more emulation devices may perform theone or more, or all, functions while being temporarilyimplemented/deployed as part of a wired and/or wireless communicationnetwork. The emulation device may be directly coupled to another devicefor purposes of testing and/or may performing testing using over-the-airwireless communications.

The one or more emulation devices may perform the one or more, includingall, functions while not being implemented/deployed as part of a wiredand/or wireless communication network. For example, the emulationdevices may be utilized in a testing scenario in a testing laboratoryand/or a non-deployed (e.g., testing) wired and/or wirelesscommunication network in order to implement testing of one or morecomponents. The one or more emulation devices may be test equipment.Direct RF coupling and/or wireless communications via RF circuitry(e.g., which may include one or more antennas) may be used by theemulation devices to transmit and/or receive data.

Although the WTRU is described in FIGS. 1A-1F as a wireless terminal, itis contemplated that in certain representative embodiments such aterminal may use (e.g., temporarily or permanently) wired communicationinterfaces with the communication network.

In certain representative embodiments, a MICO WTRU 102 may determinewhether the MICO WTRU 102 performs a registration update, for examplebefore a SR according to any of: a pre-configured flag, a network (NW)(e.g., NW 113/115) provided flag and/or other criteria, among others.

In certain representative embodiments, the MICO WTRU 102 may include aTemporary User ID (TUID) of the MICO WTRU 102 in a SR which, for examplemay enable WTRU information retrieval if the serving Access and MobilityManagement Function (AMF) does not have a context (e.g., a WTRUcontext).

In certain representative embodiments, the MICO WTRU 102 may readidentifiers of serving AMFs (e.g., an AMF 182 a) from broadcast systeminformation and may compare the identifiers to one or more stored TUIDsto determine whether the MICO WTRU 102 has moved to a new AMF (e.g., anAMF 182 b).

In certain representative embodiments, the MICO WTRU 102 may indicate apreference to initiate a connection from the MICO WTRU 102 itself andthe NW (e.g., NW 113/115) may refrain from releasing the connection ofthe MICO WTRU 102 (e.g., if such a preference is accepted).

In certain representative embodiments, the MICO WTRU 102 may reject theRAN signaling, for example to place the MICO WTRU 102 into anRRC_INACTIVE mode and the MICO WTRU 102 may remain in CONNECTED modeand/or may go to IDLE mode.

If the NW (e.g., NW 113/115) determines, desires or wants to update oris to update configuration parameters for the MICO WTRU 102 (e.g.,Network Slice Selection Assistance Information (NSSAI), an extendeddiscontinuous reception (eDRX), and/or a MICO periodic timer, amongothers), the NW 113/115 may use an SR procedure to trigger the MICO WTRU102 to perform a registration procedure.

Representative MICO Mode

A “Mobile Originated Only” (MOO) function/procedure and/or feature maybe a service requirement for Machine Type Communication (MTC). Forexample, the NW (e.g., NW 113/115) may reduce frequency of mobilitymanagement procedures for MOO devices. A Power Saving Mode (PSM) featuremay address MOO for infrequent Mobile Terminated service requirements.The PSM mode may be similar to power-off, with the WTRU 102 remainingregistered. The WTRU 102 may exit (e.g., may only exit) PSM mode whenthe WTRU 102 has Mobile Originated (MO) data and/or signaling. The WTRU102 may not be reachable when the WTRU 102 is in PSM mode.

A MICO mode WTRU 102 may not be reachable (e.g., may always not bereachable) while in CM-IDLE. The core NW (CN) 115 may reject any requestfor downlink data or signaling delivery for a MICO WTRU 102 that is inIDLE mode. The WTRU 102 in MICO mode may be reachable (e.g., may be onlyreachable) for mobile terminated data and/or signaling when the MICOWTRU 102 is in CM-CONNECTED mode. A MICO WTRU 102 may initiate a CM-IDLEmode to CM-CONNECTED mode switch procedure due to any of the followingtriggers: (1) a change in the MICO WTRU 102 (e.g., a change in itsconfiguration), for example that may require and/or cause an update tothe MICO WTRU registration with the NW 113/115; (2) a registration timer(e.g., a periodic registration timer) that may expire; (3) MO data thatmay be pending; and/or (4) MO signaling that may be pending (e.g., a SMprocedure that may be initiated), among others.

The MICO WTRU 102 may negotiate with the NW 113/115 as to whether theMICO WTRU 102 may enter the MICO mode. The WTRU 102 may indicate apreference for the MICO mode during an initial registration and/or aregistration update. The AMF 182 a may determine whether the MICO modeis allowed for the WTRU 102 based on: (1) a local configuration, (2)WTRU subscription information, (3) WTRU indicated preferences; and/or(4) NW policies. The AMF 182 a may indicate the determination to theWTRU (e.g., the MICO WTRU determination) 102 during the registrationprocedure.

A “Mobile Deregistration at the End of Communication” function/procedureand/or feature, by which the WTRU 102 may perform deregistration at theend of communication without additional NAS signaling may beimplemented. The WTRU 102 may indicate a preference for DeregistrationAt the End of Communication (DAEC) during a registration procedure. TheAMF 182 a may determine whether the DAEC is supported for the WTRU, andmay indicate the support for DAEC during the registration signaling.When the AMF 182 a applies the DAEC to the WTRU 102, the AMF 182 a mayconsider that the WTRU 102 may enter RM-DEREGISTERED at the release ofan N2 connection for the WTRU 102, and that the WTRU 102 may move toRM-DEREGISTERED when leaving the CM-CONNECTED mode. This type of WTRU102 may share a common characteristic with the MICO WTRU 102 in thatboth may be unreachable except in CONNECTED mode.

Although a MICO WTRU 102 is described hereinafter, variousrepresentative embodiments herein are equally applicable to other typeof WTRUs 102 including a DAEC WTRU 102 and other mobile WTRUs 102.

In certain representative embodiments, representative procedures may beimplemented, for example to enable a MICO WTRU 102 to be recognized in aserving AMF 182.

FIG. 2 is a diagram illustrating a representative MICO WTRU 102 movingto a new serving AMF 182 b.

Referring to FIG. 2, in representative network 200, a WTRU 102 may belocated in a first registration area 210 including a first plurality oftracking areas TAl-TA4 and may be served by a first AMF 182 a. The WTRU102 may move to a second serving area 220 including a second pluralityof tracking areas TA5-TA8 that may be served by a second AMF 182 b. TheWTRU 102 (e.g., a typical WTRU or non-MICO WTRU) may be assigned thefirst registration area 210 from which the WTRU is being served and mayperform a registration area update when the WTRU 102 leaves theconfigured registration area (e.g., the first registration area 210).The NW 113/115 may limit the paging area to the registration area 210 or220 of the WTRU 102. MICO WTRUs 102 are not supposed to and/or do notreceive paging in IDLE mode and a normal registration area configurationmay not be used for the MICO WTRUs 102. A WTRU 102 in a MICO mode(hereafter sometimes referred to as a MICO WTRU) may be assigned an “allPLMN” registration area such that the MICO WTRU 102 may not performregistration area updates (e.g., except for periodic registrationupdate) when the MICO WTRU 102 remains in the same registered PLMN. TheMICO WTRU 102 may move into a new area which is not served by the firstAMF 182 a that the MICO WTRU 102 previously registered with. Forexample, a new AMF (e.g., the second AMF 182 b) may be selected to servethe MICO WTRU 102 when the MICO WTRU 102 is to initiate a connection(e.g. with a SR message and/or a periodic registration update). The newAMF (e.g., the second AMF 182 b) may reject the SR or the periodicregistration update (e.g., because the new AMF 182 b may not recognizethe MICO WTRU 102), which may trigger the MICO WTRU 102 to registeragain.

For example, first, the MICO WTRU 102 may be registered with the oldserving AMF 182 a using a WTRU context via a gNB 180 a. Then, the MICOWTRU 102 may move to a new area without registration. Next, the MICOWTRU 102 may send a SR to a new serving AMF 182 b via a new gNB 180 c.Last the AMF may send a service reject to the MICO WTRU 102 via the gNB180 c, for example because the AMF 182 b does not recognize the MICOWTRU 102.

If this scenario happens frequently (e.g., more frequently, for example,above a threshold level), the “service-reject-then-re-register” approachmay significantly delay the mobile initiated communication and mayimposes extra signaling overhead to the NW 113/115.

For example, registration may be performed by the MICO WTRU 102 beforean SR, for example to avoid a Service Reject, and to avoid extrasignaling overhead. The MICO WTRU 102 may be provided, by the NW113/115, a Within Serving AMF (WSA) area, which may be a list ofTracking Areas, and, for example, may enable the MICO WTRU 102 todetermine whether the MICO WTRU 102 is within (e.g., still within) theserving area of the registered AMF 182 a. When (e.g., only when) theMICO WTRU 102 determines that the MICO WTRU 102 is outside of theserving area of the registered AMF 182 a, the MICO WTRU 102 may initiatethe registration procedure before any originated communication.

Representative Procedures to Keep a MICO WTRU in CONNECTED Mode

In general, a RAN 113 (e.g., including one or more gNBs 180) mayinitiate a connection release according to one or more conditions suchas inactivity (e.g., user inactivity) and/or radio communicationfailure. For example, the RAN 113 may maintain an inactivity timer forthe WTRU 102 and when no data activity is detected before the timerexpires, the RAN 113 may initiate the connection release. For the MICOmode, the WTRU 102 is only reachable in the CONNECTED mode. If theconnection is released prematurely and data is still pending, there maybe no way to bring the MICO WTRU 102 back to CONNECTED mode until thenext time the MICO WTRU 102 initiates a connection. In certainrepresentative embodiments, the WTRU 102 in the MICO mode may makeconnection release decisions. In other representative embodiments, theNW 113/115 may maintain the MICO WTRU 102 in CONNECTED mode longer,under certain criteria (e.g., when the NW 113/115 determines a longerconnection is appropriate and/or necessary).

The AMF 182 a may maintain a connection timer for the MICO WTRU 102.When the RAN 113 inactivity timer expires, the RAN 113 may request an N2connection (e.g., a signaling connection between the RAN 113 and the AMF182 a) release. If the AMF 182 a determines that the MICO WTRUconnection is not to be released according to its own connection timer,the AMF 182 a may reject the release request of the RAN 113 and the RAN113 may maintain the MICO WTRU 102 in CONNECTED mode. In certainrepresentative embodiments, a procedure may be implemented to make theAMF 182 a aware of WTRU data activities, for example to enable the AMF182 a to maintain a connection timer and/or inactivity timer. In certainrepresentative embodiments, a procedure may be implemented to preventthe RAN 113 from initiating a RRC connection release when the RAN 113requests to release the N2 connection, for example by the AMF 182 a byproviding the RAN 113 with WTRU-specific inactivity information (e.g.,timer information).

Representative Procedures to Prevent MICO WTRU from Entering RRCInactive Mode

FIG. 3 is a diagram illustrating representative states including arepresentative RRC_INACTIVE state (e.g., a New RRC_INACTIVE state) in a5G New Radio (e.g., for a WTRU 102).

Referring to FIG. 3, in a RAN 113 (e.g., a 5G RAN), RRC states 300 mayinclude any of: (1) an RRC_CONNECTED state 310; (2) an RRC_INACTIVEstate 320; and/or (3) an RRC_IDLE state 330, among others. For WTRUs 102in an INACTIVE state 320, the Core Network-Access Network (CN-AN)connection may be maintained as in the CONNECTED state 310. The CN-ANconnection may be between the (RAN) and the CN and may have both controlplane (CP) (for example, an N2 interface in 5G for signaling) and userplane (UP) (for example, an N3 interface in 5G for data) connections.The WTRU 102 in the INACTIVE state 320 may behave more like a WTRU in anIDLE mode. For example, the WTRU 102 in the INACTIVE state 320 mayfollow a cell selection/reselection procedure when the WTRU 102 changescells. The CN 115 may not be aware of the INACTIVE state 320 of the WTRU102 and may continue to consider the WTRU 102 to be in CONNECTED state310, so CN paging may not be performed towards the INACTIVE WTRU 102.Procedures may be implemented to determine by the CN 115 that the WTRU102 is in an INACTIVE state 320 and not in a CONNECTED state 310, forexample to enable proper paging of MICO WTRUs 102. As an example, whendownlink (DL) data is received from the CN 115, an anchor RAN 113 mayinitiate paging and may manage a RAN paging area for the INACTIVE WTRU102. In certain representative embodiments, conditions may be set forththat trigger a state switch between the RRC_INACTIVE state 320 and oneof the two other states 310 or 330.

The benefit of having an INACTIVE state 320 may include power saving andreduced signaling overhead (for example brought by the frequentRRC_IDLE< >RRC_CONNECTED switch). For MICO WTRUs 102, both the powersaving and signal reduction benefit may not be useful and/or needed, andputting a MICO WTRU 102 in an RRC_INACTIVE mode/state 320 may incurpotential technical complexities. As such, in certain representativeembodiments, the MICO WTRU 102 may be prevented from entering theRRC_INACTIVE state 320.

Representative Procedures Having Long Periodic Timer (e.g., to Preventthe WTRU from Performing Registration Update)

When a WTRU 102 informs the NW 113/115 of certain configurationmodifications or negotiates certain parameters, the WTRU 102 may triggercertain registration update procedures such as a Routing Area Update(RAU) and/or a Tracking Area Update (TAU). The registration update maybe done, for example for the WTRU 102 to inform the NW 113/115 of someinternal changes including any of: (1) a DRX Cycle, and/or (2) certaincapability parameters, among others. When the WTRU 102 triggers the RAUprocedure and/or the TAU procedure, the NW 113/115 may reply with an“Accept” message. The “handshake” may work as a negotiation between thetwo entities.

It is contemplated that for 5G systems, there may bescenarios/situations where the WTRU 102 (e.g., a MICO WTRU) may not havea chance to start a registration update procedure, (for example, whenthe WTRU 102 has a long periodic registration timer). During an IDLEmode 330, if a periodic registration timer is running (since the WTRU102 may only send registration update message when the periodic timerexpires), the WTRU 102 may send a SR message. The periodic registrationtimer may be reset when the WTRU 102 goes back to the IDLE mode 330. Thesame situation may occur while the periodic timer is running. The WTRU102 may not be able to perform the registration procedure for a longtime. In certain representative embodiments, procedures may beimplemented for the WTRU 102 to negotiate with the NW 113/115 in case ofsome internal configuration changes, and/or for any other reason.

Representative Procedures for MICO WTRUs with “all PLMN” RegistrationArea

When a MICO WTRU 102, which is configured with an “all PLMN”registration area, moves to a new area that is outside of the servingarea (e.g., scope) of its registered AMF 182 a, the MO connectionrequest (e.g. SR) may be rejected by the new serving AMF 182 b and theWTRU 102 may have to re-register with the new AMF 182 b before the WTRU102 can communicate. If the MICO WTRU 102 always performsre-registration preventively before SR, for example to avoid potentialservice rejections, signaling may be wasted when the WTRU 102 is stillin the serving area 210 of the registered AMF 182 a. In certainrepresentative embodiments, procedures may be implemented, for exampleto ensure that unnecessary re-registration does not take place often.

In certain representative embodiments, the MICO WTRU 102 may receive anindication from a NW entity (e.g., of the NW 113/115) that the MICO WTRU102 should (e.g., should always) or is to perform a registrationprocedure before a connection request. The indication may be sent in thesame Registration Accept message that confirms an MICO mode for the WTRU102. The NW 113/115 may choose to set the indication when the NW 113/115configures the “all PLMN” registration area for the MICO WTRU 102. Anyof the following may be taken into consideration for setting theindication including:

-   -   (1) if the profile of the WTRU 102 indicates that the        communication of the WTRU 102 (communication needs and/or uses        of the WTRU 102) may be or is infrequent (e.g., very infrequent        or below a threshold level), the NW 113/115 and/or a NW entity        180, 182-184 may choose to set and/or may set the indication.        Even though the re-registration procedure before connection        request sometimes may not be necessary and/or appropriate, the        re-registration procedure may be tolerated (for example, because        the re-registration procedure may not or does not happen often        (e.g., above a threshold level)). In certain representative        embodiments, the profile of the WTRU 102 may indicate that the        WTRU's communication needs may be frequent and the NW 113/115        (e.g., a NW entity 180, 182-185) should not or is not to set the        indication.    -   (2) if the “mobility pattern” of the WTRU 102 indicates that the        WTRU 102 moves frequently and a roaming range of the WTRU 102 is        beyond a serving area 210 of the AMF 182 a (e.g., which may mean        that the WTRU 102 is likely (e.g., more likely), for example        above a threshold rate, to be out of the serving area 210 of the        AMF 182 a), the NW 113/115 and/or a NW entity 180, 182, 183, 184        and/or 185 may set (e.g., choose to set) the indication. If the        mobility pattern of the WTRU 102 indicates that the WTRU 102 is        stationary, substantially stationary and/or roams (e.g., only        roams) in an area (e.g., a limited area), the NW 113/115 and/or        a NW entity 180, 182, 183, 184 and/or 185 may not set the        indication.

FIG. 4 is a diagram illustrating a representative registration procedure400 in which the NW 113/115 (e.g., the AMF 182 a or another NW entity182-185) may provide “always register before service request” (alwaysRBSR) indication to the WTRU 102.

Referring to FIG. 4, at 410 a WTRU 102 may send a registration requestincluding information indicating a MICO mode preference to an AMF 182 a.At 420, the AMF 182 a may check the WTRU profile, mobility patterns andother information regarding the WTRU 102. At 430, the AMF 182 a may senda registration accept including information indicating that a MICO modeaccepted and the always RBSR indication to the WTRU 102. In certainrepresentative embodiments, the always RBSR indication may bepre-configured, for example in the MICO WTRU 102. The WTRU 102 mayinclude the pre-configured indication, together with a MICO modepreference, during the registration procedure.

If a WTRU 102 is in the MICO mode and this always RBSR indication isset, for example by signaling from the NW 113/115 (e.g., the AMF 182and/or other NW entity 183-185) and/or via a preconfiguration, the WTRU102 may check the following criteria to determine whether the WTRU 102may or is to perform the RBSR (e.g., the always RBSR).

The NW 113/115 (e.g., the AMF 182) and/or the WTRU 102 may determinewhether the WTRU 102 has been configured with an “all PLMN” registrationarea. If the NW 113/115 and/or the WTRU 102 determines that the WTRU 102has not been configured with the “all PLMN” registration area, the WTRU102 may not perform (e.g., may not necessarily perform) the RBSR (e.g.,always RBSR). For example, the WTRU 102 may not send a registrationrequest with an MICO preference and/or the AMF 182 executing a check ofthe profile of the WTRU 102 may not send a registration accept thatincludes an indication that: (1) the MICO mode is accepted; and/or (2)an always RBSR indication.

The WTRU 102 may determine whether the WTRU 102 has moved out (e.g.,really moved out) of its Tracking Area (TA) (e.g., that the WTRU 102 hasmoved (e.g., just moved) from a previous TA to a new TA). The WTRU 102may read the TA identifier of the current TA when the WTRU 102 wakes upfor mobile originated service, and may compare the current TA identifier(e.g., which was read) to the stored TA identifier. If the current TAidentifier and the stored TA identifier are the same, the WTRU 102 maynot have moved out of the TA from which the WTRU 102 previouslyregistered with the NW 113/115 (e.g., the AMF 182 or other NW entity183-185). The WTRU 102 may not perform registration again, for examplebecause the WTRU 102 is still within the service area of the previouslyregistered AMF 182.

If the WTRU 102 has determined that the WTRU 102 may or is to perform aRegistration update procedure before a SR, the WTRU 102 may initiate theRegistration with a flag (e.g., an “Active Flag”) that may indicate thatdata is or may be pending after the Registration procedure. In thiscase, the following SR message may not be sent.

FIG. 5 is a diagram illustrating a representative determinationprocedure 500 (e.g., for the MICO WTRU 102 to determine (e.g., todecide) whether registration should, may or is to be performed before aSR).

Referring to FIG. 5, the representative determination procedure 500 mayinclude, at block 510, in the WTRU 102, a connection request beingreceived from an upper layer. At block 520, the WTRU 102 may determinewhether a SR is desired and/or need to be sent to the NW 113/115 basedon the connection request. If a SR is not desired and/or need to be sentto the NW 113/115, at block 530, the WTRU 102 may send one or moreperiodic registration updates. If a SR is desired and/or need to be sentto the NW 113/115, at block 540, the WTRU 102 may determine whether aMICO mode is set. If the MICO mode is not set, processing moves to block585 to send the SR. If the MICO mode is set, at block 550, the WTRU 102may determine that an “all PLMN” registration area is set. If the “allPLMN” registration area is not set, processing moves to block 585 tosend the SR. If the “all PLMN” registration area is set, at block 560,the WTRU 102 may determine whether an “always-register” indication isset. If the always-register indication is not set at block 560,processing moves to block 585 to send the SR. If the always-registerindication is set, at block 565, the Tracking Area ID may be read (e.g.,the most up to date Tracking Area ID may be read). At block 570, theWTRU 102 may compare the latest Tracking Area ID with the storedtracking area IDs to determine if a match exists. If a match exists atblock 570, processing moves to block 585 to send the SR (e.g., withoutany prior registration update) (as the WTRU 102 is still within atracking area that the NW 113/115 may associate with the WTRU 102). If amatch does not exist, at block 575, the WTRU 102 may store the latesttracking area. At block 580, the WTRU 102 may register the WTRU 102 withthe NW 113/115 (as the WTRU 102 is no longer within a tracking area thatthe NW 113/115 associates with the WTRU 102 such that a service rejectcan occur). At block 585, the WTRU 102 may send the SR to the NW113/115.

FIG. 6 is a diagram illustrating another representative determinationprocedure to determine whether registration should, may or is to beperformed before a SR.

Referring to FIG. 6, the representative determination procedure 600 mayinclude, at block 610, in the WTRU 102, a connection request beingreceived from an upper layer. At block 620, the WTRU 102 may determinethat a SR is desired and/or need to be sent to the NW 113/115 based onthe connection request. At block 630, the WTRU 102 may determine whethera MICO mode is set. If the MICO mode is set, at block 640, the WTRU 102may determine that an “all PLMN” registration area is set. If the MICOmode is not set, processing may move to block 690 to send a SR to the NW113/115 (e.g., without any prior registration update). If the “all PLMN”registration area is set, at block 650, the WTRU 102 may determinewhether an “always-register” indication is set. If the all PLMN”registration area is not set, processing may move to 660 to receive aTracking Area ID from broadcast system information and/or a mobileoriginated operation. If the always-register” indication is not set,processing may move to block 690 to send a SR to the NW 113/115 (e.g.,without any prior registration update). If the always-register”indication is set or processing has moved from block 640 to block 660,the Tracking Area ID is received and/or read from broadcast systeminformation and/or a mobile originated operation. At block 670, the WTRU102 may compare the received/read Tracking Area ID with one or morestored Tracking Area IDs to determine if a match exists. If a matchexists, at block 670, processing moves to block 690 to send the SR(e.g., without any prior registration update) (as the WTRU 102 is stillwithin a tracking area that the NW 113/115 associates with the WTRU102). If a match does not exist, at block 680, the WTRU may store thereceived Tracking Area ID. At block 685, the WTRU 102 may register theWTRU 102 with the NW 113/115 (as the WTRU 102 may no longer be within aTracking Area that the NW 113/115 can associate with the WTRU 102 suchthat a Service Reject can occur). At block 690, the WTRU 102 may sendthe SR to the NW 113/115.

Although the determination of whether the WTRU is in a registration areais disclosed to be based on Tracking Area Identifiers (TA IDs), one ofskill in the art understands that it may be based on AMF IDs, inaddition to or in lieu of TA IDs. For example, a received AMF Identifier(ID) may be matched to one or more stored AMF IDs to provide a similarregistration area determination.

In certain representative embodiments, the MICO WTRU 102 may include aMICO mode indication and/or a TUID of the MICO WTRU 102 in the SRmessage. In other representative embodiments, the TUID being included inthe SR may imply the MICO mode indication (e.g., a MICO mode preference)at the same time. In legacy WTRUs 102, triggering of the SR procedure isbased on the whether the WTRU 102 is “registered” in the TA (e.g., on aTA list). The legacy WTRUs 102 do not provide any “area information” tothe CN 115 when starting the SR procedure.

In certain representative embodiment, the WTRU 102 may or is to add aprevious TA Identifier of the WTRU 102 to the SR message. The AMF 182 afrom the added previous TA Identifier may identify (e.g., uniquelyidentify) the WTRU 102, in case the WTRU 102 was allocated a TUID by thesame AMF 182 a. If the serving AMF 182 b is a new AMF (e.g., the servingAMF 182 b did not previously serve the WTRU 102) and/or the serving AMF182 b may not have a context of the WTRU 102, the new AMF 182 b may notreject the SR, if the new AMF 182 b receives: (1) the MICO indication,(2) the TUID and/or (3) the TA Identifier of where the WTRU 102 wasallocated the TUID.

The new AMF 182 b may map the information (e.g., all of the information)to an address of the old AMF 182 a and may retrieve the WTRU contextfrom the old AMF 182 a, which may be derived from the TUID. The new AMF182 b may re-allocate a new TUID for the WTRU 102 after the SR procedureis handled.

FIG. 7 is a diagram illustrating a representative SR triggered WTRUcontext retrieval procedure from an old AMF 182 a (e.g., from an AMFthat previously served the WTRU 102).

Referring to FIG. 7, the SR triggered WTRU context retrieval procedure700 may include, at 720, that the WTRU 102 sends toward a new AMF 182 bthat serves the WTRU 102, an SR including, for example, a MICO modeindication (e.g., a MICO preference) and/or a TUID. At 730, the RAN 113(e.g., a gNB 180) may forward the information from the SR via an N2message to the new AMF 182 b. At 740, the new AMF 182 b may send anInformation Request including the TUID of the WTRU 102 to the old AMF182 a. At 750, the old AMF 182 a may send an Information Responseincluding, for example, a Subscriber Permanent Identification (SUPI)(which may be similar to an IMSI) and/or a Mobility Management (MM)context (e.g., a collection of information related to UE's mobilitymanagement). At 760, an authentication/security operation may beperformed between the WTRU 102 and the new AMF 182 b and between the newAMF 182 b and an AUthentication Server Function (AUSF) 710 (e.g., thenetwork function that may handle WTRU authentication).

At 770, the new AMF 182 b may send an N2 message to the RAN 113. The N2message may include information to be sent via the RAN 113 to the WTRU102 to enable a RRC Connection Reconfiguration. At 780, the RAN 113 may,based on the N2 message, send a RRC Connection Reconfiguration to theWTRU 102. At 790, the new AMF 182 b may send a WTRU configurationincluding a new TUID toward the WTRU 102 via the RAN 113. At 795, theRAN 113 may forward the WTRU Configuration to the WTRU 102.

In certain representative embodiments, the RAN 113 in the NW 113/115 maybroadcast a list of identifiers of the AMFs 182 whose serving areacovers the RAN 113. The whole or part of the identifier of the AMF 182may be broadcasted. If an AMF identifier appears in the broadcastinformation of the RAN 113, the RAN 113 is within the serving area ofthe AMF 182.

When a MICO WTRU 102 has a pending SR, the MICO WTRU 102 may read (e.g.,may first read) the AMF identifiers from the RAN broadcasted informationand may compare these AMF identifiers to the AMF ID section of thestored TUID. The AMF ID in the TUID is associated with the AMF 182, withwhich the WTRU 102 has registered, if the same AMF ID appears in thebroadcast information of the current RAN and the WTRU 102 is within(e.g., still within) the serving area of the last registered AMF 182. Inthis case, the WTRU 102 may send an SR, for example, immediately (e.g.,right away). In certain representative embodiments, the WTRU 102 mayinitiate a registration procedure prior to or before sending the SR(e.g., first initiate a registration procedure and then send an SR, forexample only sending the SR after the registration of the WTRU 102).

FIG. 8 is a diagram illustrating a Registration/SR procedure.

Referring the FIG. 8, the Registration/SR procedure 800 may include, atblock 810, in the WTRU 102, a connection request being received from anupper layer. At block 820, the WTRU 102 may determine whether a SR isdesired and/or need to be sent to the NW 113/115 based on the connectionrequest. If an SR is not desired and/or need to be sent to the NW113/115, at block 830, the WTRU 102 may send one or more periodicregistration updates. If the SR is desired and/or need to be sent to theNW 113/115, at block 840, the WTRU 102 may determine whether a MICO modeis set. If the MICO mode is not set, processing may move to block 890 tosend the SR. If the MICO mode is set, at block 850, the WTRU 102 maydetermine that an “all PLMN” registration area is set. If the “all PLMN”registration area is not set, processing may move to block 890 to sendthe SR. If the “all PLMN” registration area is set, at block 860, theWTRU 102 may read the AMF IDs from broadcast system information. Atblock 870, the WTRU 102 may compare the read AMF ID associated with theTUID with the AMF IDs from the broadcast system information (e.g., inthe list of AMF IDs) to determine whether the AMF ID associated with theTUID of the WTRU 102 is in the list.

If the AMF ID of the AMF 182 associated the TUID of the WTRU is in thelist at block 870, processing may move to block 890 to send the SR(e.g., without any prior registration update) (as the WTRU 102 is stillserved by one of the AMFs 182, for example broadcast in the systeminformation. If the AMF ID associated with the TUID of the WTRU 102 isnot in the list, at block 880, the WTRU 102 may register the WTRU 102with the NW 113/115 (as the WTRU 102 may no longer be served by a AMF182 corresponding to a AMF ID on the list such that a service reject canoccur). At block 890, the WTRU 102 may send the SR to the NW 113/115(e.g., the AMF 182).

For example, the WTRU 102 may determine if the WTRU 102 is within theAMF's service area 210 or 220 by reading AMF IDs in the SystemInformation (SI).

In certain representative embodiments, the MICO WTRU 102 may start orrestart a timer after a registration (e.g., each registration, forexample including periodic registration updates). The length of thetimer may indicate the period of time since a last registration (e.g.,during which period, the WTRU 102 is likely to be within (e.g., still bewithin) the service area 210 or 220 of the registered AMF 182 a or 182b). When the MICO WTRU 102 needs to or is to send a SR, the MICO WTRU102 may check if the timer is running. If the timer is running, the WTRU102 is likely (e.g., very likely, for example above a threshold level)to be within the same service area 210 or 220 of the last registered AMF182 a or 182 b and the MICO WTRU 102 may send the SR, for exampleimmediately and/or right away. In certain representative embodiments,the WTRU 102 may or is likely to be out of the service area 210 or 220of the last registered AMF 182 a or 182 b and the MICO WTRU 102 mayperform (e.g., may need to perform) registration again before sendingthe SR. The length of the timer may be preconfigured in the WTRU 102 orprovided by the NW 113/115 (e.g., the AMF 182 or other NW entity 180,and 183-185).

Representative Procedure for Keeping MICO WTRU in Connected Mode

To keep the MICO WTRU 102 in CONNECTED mode longer (e.g., reasonablylonger or for more than a threshold period), the NW 113/115 (e.g., theAMF 182 or other NW entities 180, 183-185) may determine that the WTRU102 has a requirement (e.g., to remain in CONNECTED mode). The NW113/115 may have difficulty to make this determination based on the WTRUprofile. Certain assistance information from the WTRU 102 may be used inthis determination.

In certain embodiments, the MICO WTRU 102 may include in the SR anindication of the characteristics of the service which enables the NW113/115 to determine that the WTRU 102 is to be or needs to be kept inCONNECTED mode longer than usual. The indication of the servicecharacteristics may include (1) a delay tolerance value and/or a“high-level delay-tolerant” indicator; and/or (2) a latency value and/or“high-latency” indication, among others, for example to provide athreshold that may be: (1) WTRU-specific; (2) application-specific; (3)service-specific; and/or (4) class-specific (e.g., deviceclass-specific) among others. For example, a specific WTRU 102 may havea specific delay tolerance, a specific latency, a specific applicationexecuting, a specific service requirement, and/or a specific deviceclass, among others that may be considered when the MICO WTRU 102 is inthe CONNECTED mode (for example to avoid prematurely moving into anothermode (e.g., disconnecting)).

In certain representative embodiments, the MICO WTRU 102 may include inthe SR information or a flag indicating a preference that the connectionrelease may be or is to be initiated by the WTRU 102 itself and notinitiated by the NW (e.g., the RAN 113 or the CN 115). After receivingthe SR with the preference indication, the NW 113/115 may determinewhether to allow the WTRU 102 to initiate (e.g., whether the RAN 113 orthe NW 113/115 is allowed to let the WTRU 102 initiate) the connectionrelease based on WTRU subscription data and/or NW policies. Ifconnection release by the WTRU 102 is accepted, the NW (e.g., the CN 115or the RAN 113) may instruct the other one of the RAN 113 or the CN 115)not to initiate the connection release for the WTRU 102. When the WTRU102 has determined autonomously (e.g., by itself) that the WTRU 102 hasfinished data communication, the WTRU 102 may initiate a connectionrelease through any of: (1) a NAS procedure and/or (2) a RRC procedure.The WTRU 102 may start a timer after the WTRU 102 enters the CONNECTEDmode. If the timer expires and the data communication of the WTRU 102 isnot completed and/or the WTRU 102 cannot determine whether the datacommunication is completed, the WTRU 102 may or is to initiate aconnection release (e.g., a connection release anyway).

FIG. 9 is a diagram illustrating a representative MICO WTRU initiatedConnection release procedure.

Referring to FIG. 9, the representative MICO WTRU initiated Connectionrelease procedure 900 may include, at 910, a registration between theAMF 182 a and the MICO WTRU 102 via the RAN 113. The registration mayinclude MICO mode information indicating that the WTRU is in a MICOmode. At 920, the MICO WTRU may send a SR via the RAN 113 to the AMF 182a and may include information indicating that the WTRU 102 prefers aWTRU initiated Connection release (for example to reduce and/orsubstantially eliminate a premature release by the NW 113/115). At 930,the NW 113/115 (e.g., via the AMF 182 a) may accept the WTRU'spreference according to and/or based on a profile of the MICO WTRU 102and one or more network policies. At 940, the AMF 182 a may send a N2message to the RAN 113 (e.g., the gNB 180) to establish the preference(e.g., for a WTRU initiated Connection release). At 950, the MICO WTRU102 may determine that data communication is complete. In certainrepresentative embodiments, at 960, 970 and 980, the WTRU 102 mayinitiate and complete a connection release via a NAS initiated message.In other representative embodiments, at 985 and 990, the WTRU 102 mayinitiate and complete a connection release via a RRC initiated message.

In a first option, at 960, the WTRU 102 may send a NAS release requestto the AMF 182 a via the RAN 113. At 970, an N2 connection release isperformed between the AMF 182 a and the RAN 113. At 980, the RAN 113 maysend a RRC Connection Release to the WTRU 102 to release the RRCconnection. In a second option, at 985, the WTRU 102 may send a RRCConnection Release Request to the RAN 113. At 990, an N2 connectionrelease is performed between the AMF 182 a and the RAN 113.

At 995, the MICO WTRU 102 may enter RRC_IDLE mode after either the firstor second option is complete.

In certain representative embodiments, the MICO WTRU 102 may in the SRinclude information indicating a preferred “inactivity time period”before the connection may be released. The NW 113/115 may determinewhether the WTRU 102 preferred inactivity period indicated in the SR maybe accepted based on WTRU subscription data and/or NW policies. If theWTRU preferred inactivity period indicated in the SR is accepted, the NW(e.g., CN 115) may instruct the RAN 113 to set the “inactivity timer”based on the preferred inactivity period value.

The representative procedures described herein may apply to MICO WTRUsthat perform deregistration at the end of a communication.

Representative Procedures for Preventing MICO WTRUs from Entering anRRC_INACTIVE State

FIG. 10 is a diagram illustrating a representative procedure in which aRAN is aware of (e.g., made aware of) a MICO mode of a WTRU via N2signaling.

Referring to FIG. 10, in the representative procedure 1000, at 1010, aregistration is performed between the AMF 182 a and the MICO WTRU 102via the RAN 113. The registration may include MICO mode informationindicating that the WTRU is in a MICO mode. At 1020, the MICO WTRU 102may send a RRC Connection Request to the RAN 113. At 1030, the RAN 113may send a RRC Connection Setup to the WTRU 102. At 1040, the MICO WTRU102 may send a RRC Connection Setup Complete to the RAN 113 which mayinclude an SR. At 1050, the RAN 113 may send the SR to the NW (e.g., theAMF 182 a). At 1060, the AMF 182 a may send an N2 message to the RAN113. The N2 message may include MICO mode information that may indicatethat the WTRU 102 is in the MICO mode. At 1070, the RAN 113 may storethe MICO mode indication in a WTRU context. At 1080, the RAN 113 maysend a RRC Connection Reconfiguration to the WTRU 102.

For example, the RAN 113 may be informed of the MICO mode of a WTRU 102(e.g., via an indicator or other information) by the CN 115) via N2signaling during the SR procedure. The RAN 113 may store the indicationand/or information in its WTRU context and may refrain from triggering astate switch to the RRC_INACTIVE state for the WTRU 102.

In certain representative embodiments, the WTRU 102 in the MICO mode mayinclude a MICO mode indication in the RRC Connection establishmentrequest message, for example if the RRC Connection Request is triggeredby a pending SR. If the RRC Connection Request is triggered bynon-service-request signaling (e.g., by a periodic registration update,among others) the MICO mode may be changed after the registrationprocedure is over and/or completed. In some representative embodiments,such as for those triggered by a non-SR signaling, the WTRU 102 may notinclude the MICO mode indication in the RRC Connection Request.

FIG. 11 is a diagram illustrating a representative procedure for a MICOWTRU 102 to accept or reject RAN signaling (e.g., that would place theMICO WTRU 102 into an INACTIVE state).

Referring to FIG. 11, in the representative procedure 1100, at 1110, aregistration is performed between the AMF 182 a and the MICO WTRU 102via the RAN 113. The registration may include MICO mode informationindicating that the WTRU 102 is in a MICO mode. At 1120, an RRCconnection may be established between the WTRU 102 and the RAN 113. At1120, the RAN 113 may determine that the WTRU is to be placed intoINACTIVE state (e.g., RRC_INACTIVE) according to some criterion (e.g.,an inactivity timer). At 1140, the RAN 113 may send a RRC ConnectionRelease to the WTRU 102 including information indicating a switch toRRC_INACTIVE state. In certain representative embodiments, at 1150 and1160, the WTRU 102 may reject the Connection Release. In otherrepresentative embodiments, at 1170, 1180 and 1190, the WTRU 102 mayaccept the Connection Release.

In a first option, at 1150, the WTRU 102 may send a RRC ConnectionRelease Reject to the RAN 113. The RRC Connection Release Reject mayinclude a cause code indicating “MICO mode.” At 1160, the WTRU 102 mayremain in Connected mode.

In a second option, at 1170, the WTRU 102 may send a RRC ConnectionRelease Complete to the RAN 113. The RRC Connection Release Complete mayinclude information indicating that the WTRU is entering RRC_IDLE mode.At 1180, an N2 connection release is performed between the AMF 182 a andthe RAN 113. At 1190, the WTRU 102 may enter the RRC_IDLE mode.

In certain representative embodiments, the RAN 113 may not be aware ofthe MICO mode of the WTRU 102, and may initiate a Request (e.g., via RRCsignaling, for example using a RRC Connection Release with anRRC_INACTIVE state switch instruction) to put and/or place the WTRU 102into the RRC_INACTIVE mode. The WTRU 102, in the MICO mode, may rejectthe Request (for example with a cause of “MICO mode”) and the WTRU 102may stay in the RRC_CONNECTED mode. In various representativeembodiments, the WTRU 102 may enter (e.g., directly enter) the RRC_IDLEmode upon or after the Request to enter the RRC_INACTIVE and may send aresponse message to the RAN 113 indicating that the WTRU 102 is going toenter the RRC_IDLE mode. Upon or after reception of the response messageby the RAN 113, the RAN 113 may initiate an N2 connection releasetowards the CN 115.

The representative procedures described herein may apply to MICO WTRUs102 that perform deregistration at the end of a communication.

Representative Procedures for Triggering a Registration Procedure

In certain representative embodiments, a “handshake” (e.g., a newhandshake) may be realized between the WTRU 102 and the NW 113/115during the SR procedure. The WTRU 102 may or is to indicate to the NW113/115 that the WTRU 102 wants, in addition to or in lieu of theregular and/or legacy purpose of the SR message, to inform the NW113/115 of certain configuration changes and/or parameters, for exampleby inserting a flag in the SR message. For example, a new informationelement may be defined to serve this purpose (e.g., to indicate orinform the NW 113/115 of configuration changes/parameters). On the NWside, in addition to processing the regular SR message, the NW 113/115may respond back to the WTRU 102, using a Service Accept message, tofinalize the negotiation/handshake. It is contemplated that theseprocedures/mechanisms described herein may be implemented as a newfunctionality, for example in 5G or may be realized by the WTRU 102 andthe NW 113/115 informing each other of the support during the firstregistration (e.g., during the Attach or the first Registration).

If the NW 113/115 wants and/or is to update configuration parameters forthe WTRU 102 (e.g. NW Slice Selection Assistance Information (NSSAI), aneDRX and/or a MICO periodic timer, among others), the NW 113/115 may usethe SR procedure to trigger the WTRU 102 to perform a registrationprocedure. The NW 113/115 may include an explicit indication in theService Accept or Reject message (e.g., with a cause code in the rejectmessage) informing the WTRU 102 that certain configuration parametersare to be and/or need to be updated. The reception of the flag in theService Accept or Reject message may cause the WTRU 102 to perform aregistration procedure. In certain representative embodiments, the NW113/115 (e.g., the AMF 182) may send the configuration parameters whichare to be and/or which need to be updated in the Service Accept orReject message. The WTRU 102 may perform the Registration procedure ifthe WTRU 102 receives new configuration parameters in the Service Acceptor Reject message (e.g., a Service Accept or Reject NAS message).

FIG. 12 is a flowchart illustrating a representative method offacilitating a SR.

Referring to FIG. 12, the representative method 1200 may include, atblock 1210, a WTRU 102 performing a first registration with a NE (e.g.,an AMF 182 a or another network device). The WTRU 102 may indicate tothe NW 113/115 via the NE 182 a that the WTRU 102 is operating in a MICOmode. At block 1220, the WTRU 102 may determine whether the WTRU 102 isregistered in an “all PLMN” registration area. At block 1230, oncondition that the WTRU 102 operating in the MICO mode is not registeredin the “all PLMN” registration area, the WTRU 102 may determine whetherthe WTRU 102 is outside of a registration area associated with the firstregistration based on any of: (1) location related informationassociated with the WTRU 102 received after the first registration ofthe WTRU 102; (2) information from a Mobile Originated (MO) serviceinitiated after the first registration of the WTRU 102 with the NE113/115, and/or (3) a network provided flag. At block 1240, the WTRU 102may send a SR. At block 1250, on condition that the WTRU 102 isdetermined to be outside the registration area, the WTRU 102 may performa second registration or a registration update (e.g., with another NE(e.g., the AMF 182 b) prior to the SR.

In certain representative embodiments, the WTRU 102 may obtaininformation indicating that the WTRU 102 is to initiate the secondregistration or the registration update for sending of the SR. Forexample, the WTRU 102 may perform the second registration or theregistration update by sending a registration request in accordance withthe obtained information.

In certain representative embodiments, the WTRU 102 may obtain theinformation via a preconfiguration and/or via network signaling (e.g.,signaling via the network 113/115).

In certain representative embodiments, the WTRU 102 may determine thatthe WTRU 102 is registered to an “all PLMN” registration area.

In certain representative embodiments, the WTRU 102 may determinewhether an “always register” indication is set, on condition that theWTRU 102 is registered to the “all PLMN” registration area.

In certain representative embodiments, the WTRU 102 may send aregistration request to perform the second registration (e.g., anupdate) prior to the SR, on condition that an “always register”indication is set.

In certain representative embodiments, the WTRU 102 may obtain aTracking Area (TA) identifier of a TA of the WTRU indicated in abroadcast signal. For example, the WTRU 102 may determine whether theWTRU 102 is outside of the registration area based on whether theobtained TA identifier (e.g., associated with the AMF 182 a or 182 b)matches a stored TA identifier associated with a NE (e.g., associatedwith the AMF 182 a) last serving the WTRU 102 (e.g., such that the WTRU102 is to perform the second registration or the registration updateconditioned on the obtained TA identifier (e.g., associated with the AMF182 a or 182 b) not matching the stored TA (e.g., associated with theAMF 182 a).

In certain representative embodiments, the WTRU 102 may obtain anidentifier associated with a registration area of the WTRU 102 indicatedin a broadcast signal. For example, the WTRU 102 may determine whetherthe WTRU 102 is outside of the registration area based on whether theobtained identifier matches a stored identifier associated with a NE(e.g., the AMF 182 a or other NE 180, 183-185) last serving the WTRU 102such that the performing of the second registration or the registrationupdate is conditioned on the obtained identifier not matching the storedidentifier. In certain representative embodiments, the identifier may beone of: (1) a Tracking area identifier (e.g., associated with an AMFserving a registration area); (2) a Routing Area identifier or (2) anAMF identifier (e.g., identifying an AMF serving the registration area).

In certain representative embodiments, the WTRU 102 may send the SRwithout any second registration or registration update prior to sendingthe SR, on condition that the obtained TA identifier matches the storedTA identifier.

FIG. 13 is a flowchart illustrating another representative method offacilitating a SR registration.

Referring to FIG. 13, the representative method 1300 implemented by aWTRU 102 operating in a MICO mode and registered in a first registrationarea may include, at block 1310, a WTRU 102 determining whether the WTRUis outside (e.g., located outside) of the first registration area basedon any of: (1) information from a latest Mobile Originated (MO) serviceof the WTRU 102 or (2) a network provided flag. At block 1320, the WTRU102 may perform a registration update, on condition that the WTRU 102 isdetermined to be outside the first registration area. At block 1330, theWTRU 102 may send an SR after the registration update.

FIG. 14 is a flowchart illustrating a further representative method offacilitating a SR.

Referring to FIG. 14, the representative method 1400 may include, atblock 1410, a WTRU 102 performing a first registration with a NE (e.g.,an AMF 182 a). The WTRU 102 may indicate to the NW 113/115 via the NE(e.g., the AMF 182 a) that the WTRU 102 is operating in a MICO mode. Atblock 1420, the WTRU 102 may determine whether the WTRU is registered inan “all PLMN” registration area. At block 1430, the WTRU 102 mayselectively perform, prior to the sending of a SR, a second registrationor a registration update based on the WTRU 102 not being registered inan “all PLMN” registration area and the WTRU 102 being outside of aregistration area associated with the first registration. At block 1440,the WTRU 102 may send the SR.

FIG. 15 is a flowchart illustrating an additional representative methodof facilitating a SR.

Referring to FIG. 15, the representative method 1500 may include, atblock 1510, a WTRU 102 sending a SR that includes WTRU-specificinformation. The WTRU-specific information may include: (1) anindication that the WTRU 102 is operating in a MICO mode; and/or (2) aTemporary User Identifier (TUID) of the WTRU 102. At block 1520, theWTRU 102 may receive a Connection Reconfiguration message and a WTRUConfiguration message including a new TUID, different from the TUID inthe SR.

FIG. 16 is a flowchart illustrating yet another representative method offacilitating a SR.

Referring to FIG. 16, the representative method 1600 may include, atblock 1610, a WTRU 102 receiving a broadcast signal indicating a NetworkEntity (NE) identifier associated with a NE (e.g., the AMF 182 a or 182b) currently serving the WTRU 102. At block 1620, the WTRU 102 (e.g., ASlayer, a L1 layer, a L2 layer, a MAC layer, a physical layer, or anotherlower layer, among others) may receive a connection request from ahigher layer (e.g., a NAS layer, another higher layer, among others). Atblock 1630, the WTRU 102 may determine, by a second layer (e.g., an ASlayer, a L1 layer, an L2 layer, a MAC layer, a physical layer, or theother lower layer, among others), whether the WTRU 102 is operating in aMICO mode. At block 1640, the WTRU 102 may determine whether thereceived NE identifier matches a stored NE identifier associated with aNE (e.g., the AMF 182 a) last serving the WTRU 102, on condition thatthe WTRU 102 is operating in the MICO mode. At block 1650, the WTRU 102may send a SR including WTRU-specific information, on condition that thereceived NE identifier (e.g., the AMF 182 a or 182 b) matches the storedNE identifier (e.g., the AMF 182 a).

In certain representative embodiments, the WTRU 102 may send a newregistration or a registration update prior to sending a SR, oncondition that the received NE identifier (e.g., the AMF 182 a or 182 b)does not match the stored NE identifier (e.g., the AMF 182 a).

FIG. 17 is a flowchart illustrating yet a further representative methodof facilitating a SR.

Referring to FIG. 17, the representative method 1700 may include, atblock 1710, a WTRU 102 obtaining information indicating that the WTRU isto initiate registration prior to sending a SR. At block 1720, the WTRU102 may send a registration request in accordance with the obtainedinformation. At block 1730, the WTRU 102 may send the SR afterregistering with a NE (e.g., an AMF 182 b).

In certain representative embodiments, the WTRU 102 may obtain theinformation via a preconfiguration or via network signaling.

In certain representative embodiments, the WTRU 102 may determinewhether the WTRU 102 is operating in a MICO mode and may send theregistration request prior to the SR on condition that the WTRU 102 isoperating in the MICO mode.

In certain representative embodiments, the WTRU 102 may determinewhether the WTRU 102 is registered to an “all PLMN” registration areaand may send the registration request prior to the SR on condition thatthe WTRU 102 is registered to an “all PLMN” registration area.

In certain representative embodiments, the WTRU 102 may receive abroadcast signal indicating a Tracking Area (TA) identifier of a TA ofthe WTRU 102, may receive a connection request from a higher layer, andmay determine, by a second layer, whether the WTRU 102 is operating inthe MICO mode.

In certain representative embodiments, the WTRU 102 may determine atleast whether the indicated TA identifier matches a stored TA identifierassociated with a NE (e.g., the AMF 182 a) last serving the WTRU 102, oncondition that the WTRU 102 is operating in MICO mode, and may send theSR, on condition that the indicated TA identifier matches the stored TAidentifier.

In certain representative embodiments, the WTRU 102 may send a newregistration or a registration update prior to sending the SR, oncondition that the indicated TA identifier does not match the stored TAidentifier.

FIG. 18 is a flowchart illustrating yet an additional representativemethod of accepting or rejecting a connection release.

Referring to FIG. 18, the representative method 1800 implemented by aWTRU 102 in a MICO mode may include, at block 1810, the WTRU 102receiving, from a NE (e.g., a gNB 180) of a RAN 113, a ConnectionRelease. At block 1820, the WTRU 102 may determine whether to accept theConnection Release. At block 1830, on condition that the WTRU 102accepts the Connection Release, the WTRU may: (1) send a ConnectionRelease Complete, and (2) enter into an idle mode. At block 1840, oncondition that the WTRU 102 does not accept the Connection Release, theWTRU 102 may: (1) send a Connection Release Reject with a cause codeindicating that the WTRU 102 is operating in the MICO mode, and (2)remain in a connected mode.

FIG. 19 is a flowchart illustrating a representative method implementedto facilitate a registration.

Referring to FIG. 19, the representative method 1900 implemented by aWTRU 102 may include, at block 1910, the WTRU 102 sending to a NE (e.g.,an AMF 182, or other NE such as a gNB 180, or CN entity 183-185) a firstmessage. At block 1920, the WTRU 102 may obtain information indicatingthat the WTRU 102 is to initiate registration. At block 1930, the WTRUmay send a registration request in accordance with the obtainedinformation. For example, the obtained information may be a cause codeor an indication included in a second message from the NE 180 and182-185. In certain representative embodiments, the first message may bea service request and/or the second message may be a service accept or aservice reject message. In various representative embodiments, the WTRUmay perform a registration update and may update configurationparameters based on the registration update.

FIG. 20 is a flowchart illustrating a representative method implementedby a NW to facilitate a SR.

Referring to FIG. 20, the representative method 2000 implemented by aNetwork Entity (NE) (e.g., an AMF 182, or other NE such as a gNB 180, orCN entity 183-185) may include, at block 2010, the NE 182 sendinginformation indicating that the WTRU 102 is to initiate registrationprior to sending an SR. At block 2020, the NE 182 may receive aregistration request in accordance with the obtained information. Atblock 2030, the NE 113/115 may receive the SR after the WTRU 102 isregistered.

FIG. 20 is a flowchart illustrating another representative methodimplemented by a NW when a WTRU is in MICO mode.

Referring to FIG. 21, the representative method 2100 implemented by a NE(e.g., an AMF 182, or other NE 180, 183-185) of the NW 113/115 mayinclude, at block 2110, the NE 180, 182-185 determining whether the WTRU102 is operating in a MICO mode. At block 2120, on condition that theWTRU 102 is operating in the MICO mode, the NE 180, 182-185 of the NW113/115 may: (1) set an inactivity timer for a period which is longerthan a period for a WTRU 102 not in the MICO mode; (2) prevent aconnection release of the WTRU 102 for inactivity of the WTRU 102;and/or (3) negotiate with the WTRU 102 so that the WTRU 102 isconfigured to autonomously release the connection with the NE 180,182-185 of the NW 113/115.

FIG. 22 is a flowchart illustrating a further representative methodimplemented by a NW to facilitate a connection request.

Referring to FIG. 22, the representative method 2200 implemented by a NE(e.g., an AMF 182 b, or other NE 180, 183-185) of the NW 113/115 mayinclude, at block 2210, the NE 182 b receiving a message requesting aconnection of a WTRU 102 including WTRU-specific information. At block2220, the NE 182 b may determine from the WTRU-specific information,another NE (e.g., the AMF 182 a) that last served the WTRU 102. At block2230, the NE 182 b may send to the other NE (e.g., the AMF 182 a), aninformation request for information to connect the WTRU 102 with the NE182 b.

In certain representative embodiments, the NE 182 b may receive, fromthe other NE 182 a, the requested information to connect the WTRU 102and may authenticate and connect the WTRU 102 based on the informationreceived from the other NE 182 a.

In certain representative embodiments, the WTRU-specific information mayinclude any of: (1) an indication that the WTRU 102 is operating in aMICO mode; and/or (2) a Temporary User Identifier (TUID) of the WTRU102.

FIG. 23 is a flowchart illustrating an additional representative methodimplemented by a NW to facilitate a SR.

Referring to FIG. 23, the representative method 2300 implemented by a NE(e.g., an AMF 182, or other NE 180, 183-185) of the NW 113/115 mayinclude, at block 2310, the NE 182 receiving a registration request toregister a WTRU 102 including an indication that the WTRU is operatingin a MICO mode. At block 2320 the NE 182 may receive from the WTRU 102(e.g., via a RAN 113) after registration, a SR including a preferencefor WTRU-initiated connection release of the WTRU 102. At block 2330,the NE 182 may receive from one of: (1) the WTRU 102 (e.g., via a RANentity 180 of RAN 113) a NAS release request) or (2) the RAN 113 (e.g.,the gNB 180) a N2 connection release (e.g., in accordance with a RRCConnection release request from the WTRU 102). For example, for oneoption, the WTRU 102 may send an RRC Connection release request to theRAN 113 and the RAN 113 may perform a N2 connection release with the AMF182 thereafter. At block 2340, the NE 182 may release a connectiontoward the WTRU 102.

In certain representative embodiments, the NE 182 may determine whetherto accept the preference and may send to the RAN entity (e.g., the gNB180) of the RAN 113 serving the WTRU 102 that the preference isaccepted.

In certain representative embodiments, the NE 182 may check any of: (1)a WTRU profile; or (2) a WTRU mobility pattern.

FIG. 24 is a flowchart illustrating a representative method implementedby a NW to facilitate a registration.

Referring to FIG. 24, the representative method 2400 implemented by a NE(e.g., an AMF 182, or other NE such as a gNB 180, or CN entity 183-185)may include, at block 2410, the NE 180, 182-185 receiving from the WTRU102 a first message. At block 2420, the NE 180, 182-185 may determinethat the WTRU is to initiate a registration. At block 2430, the NE 180,182-185 may send to the WTRU information indicating that the WTRU is toinitiate the registration. At block 2440, the WTRU may receive aregistration request in accordance with the sent information. Forexample, the sent information may be a cause code or an indicationincluded in a second message from the NE 180 and 182-185. In certainrepresentative embodiments, the first message may be a service requestand/or the second message may be a service accept or a service rejectmessage.

FIG. 25 is a flowchart illustrating a representative method implementedby a RAN entity to facilitate a SR.

Referring to FIG. 25, the representative method 2500 implemented by aRAN entity (RE) (e.g., a gNB 180) of the RAN 113 may include, at block2510, the RAN entity 180 receiving a message including an SR for theWTRU 102. A registration of the WTRU 102 with a Network Entity (NE)(e.g., AMF 182 may indicate that the WTRU 102 is operating in a MICOmode. At block 2520, the RE 180 may send to the NE 182 the SR. At block2530, the RE 180 may receive from the NE 182, a message includinginformation that the WTRU 102 is operating in the MICO mode. At block2540, the RE 180 may store the information that the WTRU 102 isoperating in the MICO mode in a context of the WTRU 102. At block 2550,the RE 180 may halt a trigger of a change to an RRC inactive state forthe WTRU 102 based on the stored information in the context of the WTRU102.

Although only two AMFs 182 a and 182 b are shown, any number of AMF maybe implemented in a CN 115.

Various NEs and REs are illustrated herein. These NEs may include one ormore processors, one or more transmitters and one or more receivers andone or more memories operatively communicating, and configured toexecute the method of any of the embodiments disclosed herein.

WTRUs are illustrated herein. The WTRUs may include one or moreprocessors, one or more transmitters and one or more receivers and oneor more memories operatively communicating, and configured to executethe method of any of the embodiments disclosed herein.

Although features and elements are described above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element can be used alone or in any combination with theother features and elements. In addition, the methods described hereinmay be implemented in a computer program, software, or firmwareincorporated in a computer readable medium for execution by a computeror processor. Examples of non-transitory computer-readable storage mediainclude, but are not limited to, a read only memory (ROM), random accessmemory (RAM), a register, cache memory, semiconductor memory devices,magnetic media such as internal hard disks and removable disks,magneto-optical media, and optical media such as CD-ROM disks, anddigital versatile disks (DVDs). A processor in association with softwaremay be used to implement a radio frequency transceiver for use in aWTRU, a UE, a terminal, a base station, an RNC, or any host computer.

Moreover, in the embodiments described above, processing platforms,computing systems, controllers, and other devices containing processorsare noted. These devices may contain at least one Central ProcessingUnit (“CPU”) and memory. In accordance with the practices of personsskilled in the art of computer programming, reference to acts andsymbolic representations of operations or instructions may be performedby the various CPUs and memories. Such acts and operations orinstructions may be referred to as being “executed,” “computer executed”or “CPU executed.”

One of ordinary skill in the art will appreciate that the acts andsymbolically represented operations or instructions include themanipulation of electrical signals by the CPU. An electrical systemrepresents data bits that can cause a resulting transformation orreduction of the electrical signals and the maintenance of data bits atmemory locations in a memory system to thereby reconfigure or otherwisealter the CPU's operation, as well as other processing of signals. Thememory locations where data bits are maintained are physical locationsthat have particular electrical, magnetic, optical, or organicproperties corresponding to or representative of the data bits. Itshould be understood that the exemplary embodiments are not limited tothe above-mentioned platforms or CPUs and that other platforms and CPUsmay support the provided methods.

The data bits may also be maintained on a computer readable mediumincluding magnetic disks, optical disks, and any other volatile (e.g.,Random Access Memory (“RAM”)) or non-volatile (e.g., Read-Only Memory(“ROM”)) mass storage system readable by the CPU. The computer readablemedium may include cooperating or interconnected computer readablemedium, which exist exclusively on the processing system or aredistributed among multiple interconnected processing systems that may belocal or remote to the processing system. It is understood that therepresentative embodiments are not limited to the above-mentionedmemories and that other platforms and memories may support the describedmethods.

In an illustrative embodiment, any of the operations, processes, etc.described herein may be implemented as computer-readable instructionsstored on a computer-readable medium. The computer-readable instructionsmay be executed by a processor of a mobile unit, a network element,and/or any other computing device.

There is little distinction left between hardware and softwareimplementations of aspects of systems. The use of hardware or softwareis generally (but not always, in that in certain contexts the choicebetween hardware and software may become significant) a design choicerepresenting cost vs. efficiency tradeoffs. There may be variousvehicles by which processes and/or systems and/or other technologiesdescribed herein may be effected (e.g., hardware, software, and/orfirmware), and the preferred vehicle may vary with the context in whichthe processes and/or systems and/or other technologies are deployed. Forexample, if an implementer determines that speed and accuracy areparamount, the implementer may opt for a mainly hardware and/or firmwarevehicle. If flexibility is paramount, the implementer may opt for amainly software implementation. Alternatively, the implementer may optfor some combination of hardware, software, and/or firmware.

The foregoing detailed description has set forth various embodiments ofthe devices and/or processes via the use of block diagrams, flowcharts,and/or examples. Insofar as such block diagrams, flowcharts, and/orexamples contain one or more functions and/or operations, it will beunderstood by those within the art that each function and/or operationwithin such block diagrams, flowcharts, or examples may be implemented,individually and/or collectively, by a wide range of hardware, software,firmware, or virtually any combination thereof. Suitable processorsinclude, by way of example, a general purpose processor, a specialpurpose processor, a conventional processor, a digital signal processor(DSP), a plurality of microprocessors, one or more microprocessors inassociation with a DSP core, a controller, a microcontroller,Application Specific Integrated Circuits (ASICs), Application SpecificStandard Products (ASSPs); Field Programmable Gate Arrays (FPGAs)circuits, any other type of integrated circuit (IC), and/or a statemachine.

Although features and elements are provided above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element can be used alone or in any combination with theother features and elements. The present disclosure is not to be limitedin terms of the particular embodiments described in this application,which are intended as illustrations of various aspects. Manymodifications and variations may be made without departing from itsspirit and scope, as will be apparent to those skilled in the art. Noelement, act, or instruction used in the description of the presentapplication should be construed as critical or essential to theinvention unless explicitly provided as such. Functionally equivalentmethods and apparatuses within the scope of the disclosure, in additionto those enumerated herein, will be apparent to those skilled in the artfrom the foregoing descriptions. Such modifications and variations areintended to fall within the scope of the appended claims. The presentdisclosure is to be limited only by the terms of the appended claims,along with the full scope of equivalents to which such claims areentitled. It is to be understood that this disclosure is not limited toparticular methods or systems.

It is also to be understood that the terminology used herein is for thepurpose of describing particular embodiments only, and is not intendedto be limiting. As used herein, when referred to herein, the terms “userequipment” and its abbreviation “UE” may mean (i) a wireless transmitand/or receive unit (WTRU), such as described infra; (ii) any of anumber of embodiments of a WTRU, such as described infra; (iii) awireless-capable and/or wired-capable (e.g., tetherable) deviceconfigured with, inter alia, some or all structures and functionality ofa WTRU, such as described infra; (iii) a wireless-capable and/orwired-capable device configured with less than all structures andfunctionality of a WTRU, such as described infra; or (iv) the like.Details of an example WTRU, which may be representative of any UErecited herein, are provided below with respect to FIGS. 1-5.

In certain representative embodiments, several portions of the subjectmatter described herein may be implemented via Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs),digital signal processors (DSPs), and/or other integrated formats.However, those skilled in the art will recognize that some aspects ofthe embodiments disclosed herein, in whole or in part, may beequivalently implemented in integrated circuits, as one or more computerprograms running on one or more computers (e.g., as one or more programsrunning on one or more computer systems), as one or more programsrunning on one or more processors (e.g., as one or more programs runningon one or more microprocessors), as firmware, or as virtually anycombination thereof, and that designing the circuitry and/or writing thecode for the software and or firmware would be well within the skill ofone of skill in the art in light of this disclosure. In addition, thoseskilled in the art will appreciate that the mechanisms of the subjectmatter described herein may be distributed as a program product in avariety of forms, and that an illustrative embodiment of the subjectmatter described herein applies regardless of the particular type ofsignal bearing medium used to actually carry out the distribution.Examples of a signal bearing medium include, but are not limited to, thefollowing: a recordable type medium such as a floppy disk, a hard diskdrive, a CD, a DVD, a digital tape, a computer memory, etc., and atransmission type medium such as a digital and/or an analogcommunication medium (e.g., a fiber optic cable, a waveguide, a wiredcommunications link, a wireless communication link, etc.).

The herein described subject matter sometimes illustrates differentcomponents contained within, or connected with, different othercomponents. It is to be understood that such depicted architectures aremerely examples, and that in fact many other architectures may beimplemented which achieve the same functionality. In a conceptual sense,any arrangement of components to achieve the same functionality iseffectively “associated” such that the desired functionality may beachieved. Hence, any two components herein combined to achieve aparticular functionality may be seen as “associated with” each othersuch that the desired functionality is achieved, irrespective ofarchitectures or intermediate components. Likewise, any two componentsso associated may also be viewed as being “operably connected”, or“operably coupled”, to each other to achieve the desired functionality,and any two components capable of being so associated may also be viewedas being “operably couplable” to each other to achieve the desiredfunctionality. Specific examples of operably couplable include but arenot limited to physically mateable and/or physically interactingcomponents and/or wirelessly interactable and/or wirelessly interactingcomponents and/or logically interacting and/or logically interactablecomponents.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations may be expressly set forth herein for sakeof clarity.

It will be understood by those within the art that, in general, termsused herein, and especially in the appended claims (e.g., bodies of theappended claims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, where only oneitem is intended, the term “single” or similar language may be used. Asan aid to understanding, the following appended claims and/or thedescriptions herein may contain usage of the introductory phrases “atleast one” and “one or more” to introduce claim recitations. However,the use of such phrases should not be construed to imply that theintroduction of a claim recitation by the indefinite articles “a” or“an” limits any particular claim containing such introduced claimrecitation to embodiments containing only one such recitation, even whenthe same claim includes the introductory phrases “one or more” or “atleast one” and indefinite articles such as “a” or “an” (e.g., “a” and/or“an” should be interpreted to mean “at least one” or “one or more”). Thesame holds true for the use of definite articles used to introduce claimrecitations. In addition, even if a specific number of an introducedclaim recitation is explicitly recited, those skilled in the art willrecognize that such recitation should be interpreted to mean at leastthe recited number (e.g., the bare recitation of “two recitations,”without other modifiers, means at least two recitations, or two or morerecitations). Furthermore, in those instances where a conventionanalogous to “at least one of A, B, and C, etc.” is used, in generalsuch a construction is intended in the sense one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, and C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). In those instances where aconvention analogous to “at least one of A, B, or C, etc.” is used, ingeneral such a construction is intended in the sense one having skill inthe art would understand the convention (e.g., “a system having at leastone of A, B, or C” would include but not be limited to systems that haveA alone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). It will be furtherunderstood by those within the art that virtually any disjunctive wordand/or phrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to contemplatethe possibilities of including one of the terms, either of the terms, orboth terms. For example, the phrase “A or B” will be understood toinclude the possibilities of “A” or “B” or “A and B.” Further, the terms“any of” followed by a listing of a plurality of items and/or aplurality of categories of items, as used herein, are intended toinclude “any of,” “any combination of,” “any multiple of,” and/or “anycombination of multiples of” the items and/or the categories of items,individually or in conjunction with other items and/or other categoriesof items. Moreover, as used herein, the term “set” or “group” isintended to include any number of items, including zero. Additionally,as used herein, the term “number” is intended to include any number,including zero.

In addition, where features or aspects of the disclosure are describedin terms of Markush groups, those skilled in the art will recognize thatthe disclosure is also thereby described in terms of any individualmember or subgroup of members of the Markush group.

As will be understood by one skilled in the art, for any and allpurposes, such as in terms of providing a written description, allranges disclosed herein also encompass any and all possible subrangesand combinations of subranges thereof. Any listed range can be easilyrecognized as sufficiently describing and enabling the same range beingbroken down into at least equal halves, thirds, quarters, fifths,tenths, etc. As a non-limiting example, each range discussed herein maybe readily broken down into a lower third, middle third and upper third,etc. As will also be understood by one skilled in the art all languagesuch as “up to,” “at least,” “greater than,” “less than,” and the likeincludes the number recited and refers to ranges which can besubsequently broken down into subranges as discussed above. Finally, aswill be understood by one skilled in the art, a range includes eachindividual member. Thus, for example, a group having 1-3 cells refers togroups having 1, 2, or 3 cells. Similarly, a group having 1-5 cellsrefers to groups having 1, 2, 3, 4, or 5 cells, and so forth.

Moreover, the claims should not be read as limited to the provided orderor elements unless stated to that effect. In addition, use of the terms“means for” in any claim is intended to invoke 35 U.S.C. § 112, ¶ 6 ormeans-plus-function claim format, and any claim without the terms “meansfor” is not so intended.

A processor in association with software may be used to implement aradio frequency transceiver for use in a wireless transmit receive unit(WTRU), user equipment (UE), terminal, base station, Mobility ManagementEntity (MME) or Evolved Packet Core (EPC), or any host computer. TheWTRU may be used in conjunction with modules, implemented in hardwareand/or software including a Software Defined Radio (SDR), and othercomponents such as a camera, a video camera module, a videophone, aspeakerphone, a vibration device, a speaker, a microphone, a televisiontransceiver, a hands free headset, a keyboard, a Bluetooth® module, afrequency modulated (FM) radio unit, a Near Field Communication (NFC)Module, a liquid crystal display (LCD) display unit, an organiclight-emitting diode (OLED) display unit, a digital music player, amedia player, a video game player module, an Internet browser, and/orany Wireless Local Area Network (WLAN) or Ultra Wide Band (UWB) module.

Although the invention has been described in terms of communicationsystems, it is contemplated that the systems may be implemented insoftware on microprocessors/general purpose computers (not shown). Incertain embodiments, one or more of the functions of the variouscomponents may be implemented in software that controls ageneral-purpose computer.

In addition, although the invention is illustrated and described hereinwith reference to specific embodiments, the invention is not intended tobe limited to the details shown. Rather, various modifications may bemade in the details within the scope and range of equivalents of theclaims and without departing from the invention.

1.-39. (canceled)
 40. A method implemented by a WirelessTransmit/Receive Unit (WTRU), the method comprising: performing a firstregistration, the WTRU indicating a preference for the WTRU to operatein a Mobile Initiated Communication Only (MICO) mode; after performingthe first registration and on condition that the WTRU is operating inMICO mode, sending a first service request; after sending the firstservice request, receiving a service reject message includinginformation indicating that the WTRU is to perform registration; andperforming a second registration in accordance with the service rejectmessage.
 41. The method of claim 40, wherein the information indicatingthat the WTRU is to perform registration is a cause code included in theservice reject message.
 42. The method of claim 40, wherein theinformation indicating that the WTRU is to perform registration is anexplicit indication included in the service reject message.
 43. Themethod of claim 40, further comprising: updating, by the WTRU,configuration parameters based on the second registration.
 44. Themethod of claim 40, wherein the first registration is performed with afirst network entity and the second registration is performed with thefirst network entity.
 45. The method of claim 40, wherein the firstregistration is performed with a first network entity and the secondregistration is performed with a second network entity different thanthe first network entity.
 46. The method of claim 40, wherein the firstregistration includes: sending, by the WTRU, a registration requestwhich includes information indicating the preference for the WTRU tooperating in MICO mode, and receiving, by the WTRU, a registrationaccept message which includes information indicating MICO mode isaccepted.
 47. The method of claim 40, wherein the second registration isa registration update.
 48. The method of claim 40, further comprising:after performing the second registration, sending a second servicerequest.
 49. The method of claim 48, further comprising: after sendingthe second service request, sending mobile originated data or mobileoriginated signaling.
 50. A Wireless Transmit/Receive Unit (WTRU)comprising: a processor and a transceiver configured to: perform a firstregistration, the WTRU indicating a preference for the WTRU to operatein a Mobile Initiated Communication Only (MICO) mode; after performingthe first registration and on condition that the WTRU is operating inMICO mode, send a first service request; after sending the first servicerequest, receive a service reject message including informationindicating that the WTRU is to perform registration; and perform asecond registration in accordance with the service reject message. 51.The WTRU of claim 50, wherein the information indicating that the WTRUis to perform registration is a cause code included in the servicereject message.
 52. The WTRU of claim 50, wherein the informationindicating that the WTRU is to perform registration is an explicitindication included in the service reject message.
 53. The WTRU of claim50, wherein the processor and the transceiver are configured to: updateconfiguration parameters based on the second registration.
 54. The WTRUof claim 50, wherein the first registration is performed with a firstnetwork entity and the second registration is performed with the firstnetwork entity.
 55. The WTRU of claim 50, wherein the first registrationis performed with a first network entity and the second registration isperformed with a second network entity different than the first networkentity.
 56. The WTRU of claim 50, wherein the first registrationincludes to: send a registration request which includes informationindicating the preference for the WTRU to operating in MICO mode, andreceive a registration accept message which includes informationindicating MICO mode is accepted.
 57. The WTRU of claim 50, wherein thesecond registration is a registration update.
 58. The WTRU of claim 50,wherein the processor and the transceiver are configured to: afterperforming the second registration, send a second service request. 59.The WTRU of claim 58, wherein the processor and the transceiver areconfigured to: after sending the second service request, send mobileoriginated data or mobile originated signaling.